@article {795, title = {Development of High Performance Intermediate Temperature Proton-Conducting Solid Oxide Electrolysis Cells}, volume = {80}, year = {Submitted}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {167-173}, abstract = {Steam electrolysis by solid oxide fuel cell technology, known as SOEC, is considered one of the most efficient and cost effective options for hydrogen production from renewable sources. By using proton-conducting electrolyte, the SOEC operating temperature can be reduced from over 800oC to below 600oC due to higher conductivity and lower activation energy. Technical barriers associated with the conventional oxygen-ion conducting SOECs, such as hydrogen separation from water, oxidation of steam electrode, and instability of oxygen electrode, can be largely mitigated. In this report, an intermediate temperature (500-600oC) electrolysis technology was developed where a novel proton-conductor and a triple-conducting oxide were used as the electrolyte and oxygen electrode, respectively. The electrolysis cell demonstrated excellent performance at intermediate temperatures, promising a new prospective for next-generation steam electrolysis.}, doi = {10.1149/08009.0167ecst}, url = {http://ecst.ecsdl.org/content/80/9/167.short}, author = {Dong Ding and Wei Wu and Ting He} } @article {1143, title = {Mechanistic understanding of pH effects on the oxygen evolution reaction}, journal = {Electrochimica Acta}, volume = {405}, year = {2022}, pages = {139810}, abstract = {The oxygen-evolution reaction (OER) is pivotal in many energy-conversion technologies as it is an important counter reaction to others that convert stable chemicals to higher-value products using electrochemistry. The local microenvironment and pH for the anode OER can vary from acidic to neutral to alkaline depending on the system being explored, making definitive mechanistic insights difficult. In this paper, we couple experiments, first-principles calculations based on density functional theory, microkinetics, and transport modeling to explore the entire pH range of the OER. At low current densities, neutral pH values unexpectedly perform better than the acidic and alkaline conditions, and this trend is reversed at higher current densities (> 20~mA cm-2). Using multiscale modeling, this switch is rationalized by a change from a dual-reaction mechanism to a single rate-determining step. The model also shows how the alkaline reaction rates dominate in the middle to high pH range. Furthermore, we explore that the local pH for near-neutral conditions is much different (e.g., 2.4 at the reaction surface vs. 9 in the bulk) than the pH extremes, demonstrating the criticality that transport phenomena plays in kinetic activity.}, keywords = {Electrochemistry, Microkinetics, Oxygen evolution reaction}, issn = {0013-4686}, doi = {https://doi.org/10.1016/j.electacta.2021.139810}, url = {https://www.sciencedirect.com/science/article/pii/S0013468621020934}, author = {Julie C. Fornaciari and Lien-Chun Weng and Shaun M. Alia and Cheng Zhan and Tuan Anh Pham and Alexis T. Bell and Tadashi Ogitsu and Nemanja Danilovic and Adam Z. Weber} } @article {1148, title = {Revitalizing interface in protonic ceramic cells by acid etch}, journal = {Nature}, volume = {604}, year = {2022}, month = {04}, pages = {479-485}, keywords = {acid treatment, ceramic fuel-cell, electrolysis, high-temperature annealed electrolyte surface, proton conductivity, Protonic ceramic electrochemical cells}, doi = {10.1038/s41586-022-04457-y}, author = {Bian, Wenjuan and Wu, Wei and Wang, Baoming and Tang, Wei and Zhou, Meng and Jin, Congrui and Ding, Hanping and Fan, Weiwei and Dong, Yanhao and Li, Ju and Ding, Dong} } @article {1149, title = {Spatially resolved performance and degradation in a perfluorinated anion exchange membrane fuel cell}, journal = {Electrochimica Acta}, volume = {406}, year = {2022}, pages = {139812}, abstract = {Anion exchange membrane fuel cells may enable future operation with non-precious metal-based catalysts. These systems have a delicate sensitivity to operating conditions such as humidification levels and the presence of CO2 in the air oxidant stream. We present spatially resolved in-situ performance results that shed light on phenomena that are unique to anion exchange membrane fuel cells. For cell construction, a highly conductive perfluorinated anion exchange polymer was used as the membrane and the material in powder form as the ionomer. Experiments were conducted to investigate the effects of humidification, fuel/oxidant concentration, and carbonation effects on the performance and its distribution in the cell. The results indicated that (i) dry conditions at the cathode have a stronger effect than at the anode on overall cell performance, (ii) performance significantly suffered when humidification was below 90\%, (iii) fuel and oxidant dilution effects lead mass-transport losses and were stronger than flow rate effects, (iv) CO2 in the cathode feed stream creates an equilibration disparity between the inlet and outlet sections and CO2 purging is affected by flooding conditions, and (v) after >500~h of operation, performance deteriorates predominantly at the inlet.}, keywords = {2+1D fuel cell model, Anion Exchange membranes, Cathode dry-out, CO poisoning, Fuel cell durability, Mass transport limitations, Segmented fuel cell}, issn = {0013-4686}, doi = {https://doi.org/10.1016/j.electacta.2021.139812}, url = {https://www.sciencedirect.com/science/article/pii/S0013468621020958}, author = {Ashutosh G. Divekar and Michael R. Gerhardt and Christopher M. Antunes and Luigi Osmieri and Ami C. Yang-Neyerlin and Adam Z. Weber and Bryan S. Pivovar and Guido Bender and Andrew M. Herring} } @article {1151, title = {A comprehensive modeling method for proton exchange membrane electrolyzer development}, journal = {International Journal of Hydrogen Energy}, volume = {46}, year = {2021}, note = {Special issue on the 2nd International Symposium on Hydrogen Energy and Energy Technologies (HEET 2019)}, pages = {17627-17643}, abstract = {Hydrogen attracts significant interests as an effective energy carrier that can be derived from renewable sources. Hydrogen production using a proton-exchange membrane (PEM) electrolyzer can efficiently convert renewable power via water splitting in wide scales{\textemdash}from large, centralized generation to on-site production. Mathematical models with multiple scales and fidelities facilitate the continuing improvements of PEM electrolyzer development to improve performance, cost, and reliability. The model scopes and methods are presented in this paper, which also introduces a comprehensive PEM electrolysis modeling tool based on computational fluid dynamics (CFD) software, ANSYS/Fluent. The modeling tool incorporates electrochemical model of a PEM electrolysis cell to simulate the performance of coupled thermal-fluid, species transport, and electrochemical processes in a product-scale cell or stack by leveraging the powerful meshing generation and CFD solver of ANSYS/Fluent. The thermal-fluid modeling includes liquid water/gas two-phase flow and simulates a PEM electrolysis cell by using Fluent user-defined functions as add-on modules accounting for PEM-specific species transport and electrochemical processes. The modeling outcomes expediate PEM electrolyzer scaling up from basic material development and laboratory testing.}, keywords = {Electrochemical modeling, Hydrogen production, Low temperature electrolysis water splitting, Proton exchange membrane electrolysis cell}, issn = {0360-3199}, doi = {https://doi.org/10.1016/j.ijhydene.2021.02.170}, url = {https://www.sciencedirect.com/science/article/pii/S0360319921007448}, author = {Zhiwen Ma and Liam Witteman and Jacob A. Wrubel and Guido Bender} } @article {1155, title = {Elucidating the Role of Hydroxide Electrolyte on Anion-Exchange-Membrane Water Electrolyzer Performance}, journal = {Journal of The Electrochemical Society}, volume = {168}, year = {2021}, month = {05/2021}, pages = {054522}, abstract = {Many solid-state devices, especially those requiring anion conduction, often add a supporting electrolyte to enable efficient operation. The prototypical case is that of anion-exchange-membrane water electrolyzers (AEMWEs), where addition of an alkali metal solution improves performance. However, the specific mechanism of this performance improvement is currently unknown. This work investigates the functionality of the alkali metal solution in AEMWEs using experiments and mathematical models. The results show that additional hydroxide plays a key role not only in ohmic resistance of the membrane and catalyst layer but also in the reaction kinetics. The modeling suggests that the added liquid electrolyte creates an additional electrochemical interface with the electrocatalyst that provides ion-transport pathways and distributes product gas bubbles; the total effective electrochemical active surface area in the cell with 1 M KOH is 5 times higher than that of the cell with DI water. In the cell with 1 M KOH, more than 80\% of the reaction current is associate with the liquid electrolyte. These results indicate the importance of high pH of electrolyte and catalyst/electrolyte interface in AEMWEs. The understanding of the functionality of the alkali metal solution presented in this study should help guide the design and optimization of AEMWEs.}, keywords = {alkali metal solutions, anion-exchange-membrane water electrolyzers, Energy Sciences, energy storage, liquid electrolyte, solid-state devices}, issn = {0013-4651}, doi = {10.1149/1945-7111/ac0019}, author = {Jiangjin Liu and Zhenye Kang and Dongguo Li and Magnolia Pak and Shaun M. Alia and Cy Fujimoto and Guido Bender and Yu Seung Kim and Adam Z. Weber} } @article {1156, title = {Energy Material Network Data Hubs}, journal = {International Journal of Advanced Computer Science and Applications}, volume = {12}, year = {2021}, abstract = {In early 2015 the United States Department of Energy conceived of a consortium of collaborative bodies based on shared expertise, data, and resources that could be targeted towards the more difficult problems in energy materials research. The concept of virtual laboratories had been envisioned and discussed earlier in the decade in response to the advent of the Materials Genome Initiative and similar scientific thrusts. To be effective, any virtual laboratory needed a robust method for data management, communication, security, data sharing, dissemination, and demonstration to work efficiently and effectively for groups of remote researchers. With the accessibility of new, easily deployed cloud technology and software frameworks, such individual elements could be integrated, and the required collaboration architecture is now possible. The developers have leveraged open-source software frameworks, customized them, and merged them into a platform to enable collaborative energy materials science, regardless of the geographic dispersal of the people and resources. After five years in operations, the systems are demonstratively an effective platform for enabling research within the Energy Material Networks (EMN). This paper will show the design and development of a secured scientific data sharing platform, the ability to customize the system to support diverse workflows, and examples of the enabled research and results connected with some of the Energy Material Networks.}, keywords = {cloud computing, consortium, data management, Energy materials research, network, virtual laboratories}, doi = {10.14569/IJACSA.2021.0120677}, url = {http://dx.doi.org/10.14569/IJACSA.2021.0120677}, author = {Robert R. White and Kristin Munch and Nicholas Wunder and Nalinrat Guba and Chitra Sivaraman and Kurt M. Van Allsburg and Huyen Dinh and Courtney Pailing} } @article {1117, title = {Factors Governing Oxygen Vacancy Formation in Oxide Perovskites}, journal = {Journal of the American Chemical Society}, volume = {143}, year = {2021}, pages = {13212-13227}, doi = {ttps://doi.org/10.1021/jacs.1c05570}, author = {R. B. Wexler and G. S. Gautam and E. B. Stechel and E. A. Carter} } @article {1158, title = {Influence of Supporting Electrolyte on Hydroxide Exchange Membrane Water Electrolysis Performance: Anolyte}, journal = {Journal of The Electrochemical Society}, volume = {168}, year = {2021}, month = {08/2021}, pages = {084512}, abstract = {Hydroxide-exchange-membrane water electrolysis (HEMWE) is an emerging hydrogen-production pathway that combines many advantages of incumbent alkaline water electrolysis (AWE) and proton-exchange-membrane water electrolysis (PEMWE). Advancement in HEMWE has been accelerated with the development of stable and conductive hydroxide exchange membranes (HEMs) and a more comprehensive understanding of alkaline gas-evolving kinetics. However, performance and durability without supporting electrolytes (SELs) remain inferior to PEMWE and AWE and little is known about the role and impact of the SELs. This study investigates the effects of SELs used as anolyte solutions in HEMWEs including cation-type, anion-type, SEL conductivity and pH, presence of carbonates and increased cation/OH- ratios on cell voltage and stability. We report our findings that (i) cell potential and high-frequency resistance did not correlate with anolyte SEL conductivity, (ii) cation-type influences cell voltage at low current densities (<50 mA cm-2) as predicted by half-cell measurements, (iii) increased cation/OH- ratio causes increased overpotentials, and (iv) carbonates are exchanged in the HEM but removed via self-purging at high current density. Overall, this study concludes that concentrated KOH is still the best SEL.}, keywords = {hydrogen production pathway, Hydroxide exchange membrane, incumbent alkaline, proton exchange membrane, supporting electrolytes, water electrolysis}, doi = {10.1149/1945-7111/ac1dcd}, url = {https://doi.org/10.1149/1945-7111/ac1dcd}, author = {Aleksandr Kiessling and Julie C. Fornaciari and Grace Anderson and Xiong Peng and Andreas Gerstmayr and Michael R. Gerhardt and Samuel McKinney and Alexey Serov and Yu Seung Kim and Barr Zulevi and Adam Z. Weber and Nemanja Danilovic} } @article {1160, title = {Modeling Electrokinetics of Oxygen Electrodes in Solid Oxide Electrolyzer Cells}, journal = {Journal of The Electrochemical Society}, volume = {168}, year = {2021}, month = {11/2021}, pages = {114510}, abstract = {A microscale model is presented in this study to simulate electrode kinetics of the oxygen electrode in a solid oxide electrolyzer cell (SOEC). Two mixed ionic/electronic conducting structures are examined for the oxygen producing electrode in this work: single layer porous lanthanum strontium cobalt ferrite (LSCF), and bilayer LSCF/SCT (strontium cobalt tantalum oxide) structures. A yttrium-stabilized zirconia (YSZ) electrolyte separates the hydrogen and oxygen electrodes, as well as a gadolinium doped-ceria (GDC) buffer layer on the oxygen electrode side. Electrochemical reactions occurring at the two-phase boundaries (2PBs) and three-phase boundaries (3PBs) of single-layer LSCF and bilayer LSCF/SCT oxygen electrodes are modeled under various SOEC voltages with lattice oxygen stoichiometry as the key output. The results reveal that there exists a competition in electrode kinetics between 2PBs and 3PBs, but 3PBs are the primary reactive sites for single-layer LSCF oxygen electrode under high voltages. These locations experience the greatest oxygen stoichiometry variations and are therefore the most likely locations for dimensional changes. By applying an active SCT layer over LSCF, the 2PBs become activated to compete with the 3PBs, thus alleviating oxygen stoichiometry variations and reducing the likelihood of dimensional change. This strategy could reduce lattice structural expansion, proving to be valuable for electrode-electrolyte delamination prevention and will be the focus of future work.}, keywords = {Barium zirconate, Defect transport, electrode-electrolyte delamination prevention, Faradaic efficiency, lattice oxygen stoichiometry, microscale model, o-SOEC, oxygen electrode, solid oxide electrolyzer cell}, doi = {10.1149/1945-7111/ac35fc}, url = {https://doi.org/10.1149/1945-7111/ac35fc}, author = {Korey Cook and Jacob Wrubel and Zhiwen Ma and Kevin Huang and Xinfang Jin} } @article {1120, title = {Outstanding Properties and Performance of CaTi0.5Mn0.5O3{\textendash}δ for Solar-Driven Thermochemical Hydrogen Production}, journal = {Matter}, volume = {4}, year = {2021}, pages = {688-708}, keywords = {inorganic perovskite, oxygen non-stoichiometry, phase transition, solar fuel, thermo-kinetic limit, thermochemical hydrogen production, thermodynamic properties}, doi = {https://doi.org/10.1016/j.matt.2020.11.016}, author = {X. Qian and J. He and E. Mastronardo and B. Baldassarri and W. Yuan and C. Wolverton and S. M. Haile} } @article {1164, title = {Regulation of Cathode Mass and Charge Transfer by Structural 3D Engineering for Protonic Ceramic Fuel Cell at 400 {\textdegree}C (Adv. Funct. Mater. 33/2021)}, journal = {Advanced Functional Materials}, volume = {31}, year = {2021}, pages = {2170244}, abstract = {3D Engineering In article number 2102907, Wei Wu, Meng Zhou, Dong Ding, and co-workers develop a 3D engineered cathode to enhance oxygen reduction reaction kinetics on a proton-conducting fuel cell at <600 {\textdegree}C. The results demonstrate remarkable cell performance at 400{\textendash}600 {\textdegree}C by effectively regulating the mass and charge transfer through the electrode and across the interface of electrolyte and electrode.}, keywords = {3D engineering, charge transfer, mass transfer, oxygen reduction reaction, p-SOEC, protonic ceramic fuel cells}, doi = {https://doi.org/10.1002/adfm.202170244}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202170244}, author = {Bian, Wenjuan and Wu, Wei and Gao, Yipeng and Gomez, Joshua Y. and Ding, Hanping and Tang, Wei and Zhou, Meng and Ding, Dong} } @article {1165, title = {Scaleup and manufacturability of symmetric-structured metal-supported solid oxide fuel cells}, journal = {Journal of Power Sources}, volume = {489}, year = {2021}, pages = {229439}, abstract = {Metal-supported solid oxide fuel cells with symmetric architecture, having metal supports on both sides of the cell, are scaled up from button cell size to large 50~cm2 active area cell size. The cells remain flat after sintering assisted by the symmetric structure. Equivalent performance is achieved for button cells and large cells, and thermal cycling and redox cycling tolerance are demonstrated for the large cells. The catalyst infiltration process is improved to enable high-throughput manufacturing. The cumbersome lab-scale molten nitrate infiltration process is replaced with a room-temperature process in which a shelf-stable aqueous solution of nitrate salts is applied to the cell by spraying, painting, or other scalable techniques. A fast-ramp thermal conversion of the nitrate salts to the final oxide catalyst composition is implemented, allowing many infiltration cycles to be accomplished in a single work shift. Increasing the number of infiltration cycles from 5 to 10 led to an increase in peak power density from approximately 0.3 to 0.52~W~cm-2.}, keywords = {infiltration, Metal-supported, Scale up, SOFC}, issn = {0378-7753}, doi = {https://doi.org/10.1016/j.jpowsour.2020.229439}, url = {https://www.sciencedirect.com/science/article/pii/S0378775320317225}, author = {Emir Dogdibegovic and Yuan Cheng and Fengyu Shen and Ruofan Wang and Boxun Hu and Michael C. Tucker} } @article {1115, title = {Sensitivity and Effective Parameterization of a Multi-Scale Model of Proton-Exchange-Membrane Water Electrolysis}, journal = {ECS Transactions}, volume = {104}, year = {2021}, pages = {417-427}, doi = {https://doi.org/10.1149/10408.0417ecst}, author = {A. Dizon and J. Fornaciari and M. Rochow and A. Z. Weber} } @article {1127, title = {CeTi2O6{\textemdash}A Promising Oxide for Solar Thermochemical Hydrogen Production}, journal = {ACS Applied Materials \& Interfaces}, volume = {12}, year = {2020}, pages = {21521-21527}, keywords = {brannerite structure, Cerium based oxides, CeTi2O6, high thermal stability, large entropy of reduction, small reduction enthalpy}, doi = {CeTi2O6{\textemdash}A Promising Oxide for Solar Thermochemical Hydrogen Production}, author = {S. S. Naghavi and J. He and C. Wolverton} } @article {1169, title = {Degradation of solid oxide electrolysis cells: Phenomena, mechanisms, and emerging mitigation strategies{\textemdash}A review}, journal = {Journal of Materials Science \& Technology}, volume = {55}, year = {2020}, note = {SI: Energy Conversion \& Storage Materials Design, Fabrication and Functionality}, pages = {35-55}, abstract = {Solid oxide electrolysis cell (SOEC) is a promising electrochemical device with high efficiency for energy storage and conversion. However, the degradation of SOEC is a significant barrier to commercial viability. In this review paper, the typical degradation phenomena of SOEC are summarized, with great attention into the anodes/oxygen electrodes, including the commonly used and newly developed anode materials. Meanwhile, mechanistic investigations on the electrode/electrolyte interfaces are provided to unveil how the intrinsic factor, oxygen partial pressure pO2, and the electrochemical operation conditions, affect the interfacial stability of SOEC. At last, this paper also presents some emerging mitigation strategies to circumvent long-term degradation, which include novel infiltration method, development of new anode materials and engineering of the microstructure.}, keywords = {Degradation, Electrode/electrolyte interface, Mitigation, solid oxide electrolysis cell, Strategy}, issn = {1005-0302}, doi = {https://doi.org/10.1016/j.jmst.2019.07.026}, url = {https://www.sciencedirect.com/science/article/pii/S1005030219302464}, author = {Yi Wang and Wenyuan Li and Liang Ma and Wei Li and Xingbo Liu} } @article {1170, title = {Emergent Degradation Phenomena Demonstrated on Resilient, Flexible, and Scalable Integrated Photoelectrochemical Cells}, journal = {Advanced Energy Materials}, volume = {10}, year = {2020}, pages = {2002706}, abstract = {Abstract Photoelectrochemical (PEC) water splitting provides a pathway to generate sustainable clean fuels using the two most abundant resources on Earth: sunlight and water. Currently, most of the successful models of PEC cells are still fabricated on small scales near 1 cm2, which largely limits the mass deployment of solar-fuel production. Here, the scale-up to 8 cm2 of an integrated PEC (IPEC) device is demonstrated and its performance compared to a 1 cm2 IPEC cell, using state-of-the-art iridium and platinum catalysts with III{\textendash}V photoabsorbers. The initial photocurrents at 1 sun are 8 and 7 mA cm-2 with degradation rates of 0.60 and 0.47 mA cm-2 day-1, during unbiased operation for the 1 and 8 cm2 devices, respectively. Evaluating under outdoor and indoor conditions at two U.S. National Laboratories reveals similar results, evidencing the reproducibility of this design{\textquoteright}s performance. Furthermore, the emerging degradation mechanisms during scale-up are investigated and the knowledge gained from this work will provide feedback to the broader community, since PEC device durability is a limiting factor in its potential future deployment.}, keywords = {durability, on-sun testing, PEC cell scale-up, reproducibility, water splitting}, doi = {https://doi.org/10.1002/aenm.202002706}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202002706}, author = {Kistler, Tobias A. and Zeng, Guosong and Young, James L. and Weng, Lien-Chun and Aldridge, Chase and Wyatt, Keenan and Steiner, Myles A. and Solorzano Jr., Oscar and Houle, Frances A. and Toma, Francesca M. and Weber, Adam Z. and Deutsch, Todd G. and Danilovic, Nemanja} } @article {1126, title = {Favorable Redox Thermodynamics of SrTi0.5Mn0.5O3-δ in Solar Thermochemical Water Splitting}, journal = {Chemistry of Materials}, volume = {32}, year = {2020}, pages = {9335-9346}, keywords = {Cubic perovskite, Modeling, Perovskite, SrTi0.5Mn0.5O3-δ}, doi = {https://doi.org/10.1021/acs.chemmater.0c03278}, author = {X. Qian and J. He and E. Mastronardo and B. Baldassarri and C. Wolverton and S. M. Haile} } @article {1172, title = {Highly quaternized polystyrene ionomers for high performance anion exchange membrane water electrolysers}, journal = {Nature Energy}, volume = {5}, year = {2020}, month = {3}, keywords = {LTE; AEM electrolysis; Novel ionomer}, doi = {10.1038/s41560-020-0577-x}, author = {Kim, Yu Seung and Li, Dongguo and Park, Eun Joo and Wenlei, Zhu and Qiurong, Shi and Zhou, Yang and Tian, Hangyu and Lin, Yuehe and Serov, Alexey and Zulevi, Barr and Baca, Ehren Donel and Fujimoto, Cy and Chung, Hoon} } @article {1128, title = {Oxidation Kinetics of Hercynite Spinels for Solar Thermochemical Fuel Production}, journal = {Chemical Engineering Journal}, volume = {401}, year = {2020}, keywords = {Hercynite, In situ XPS, Reaction kinetics, Solar thermal, Thermochemical analysis}, doi = {https://doi.org/10.1016/j.cej.2020.126015}, author = {S. L. Millican and I. Androshchuk and J. T. Tran and R. M. Trottier and A. Bayon and Y. Al Salik and H. Idriss and C. B. Musgrave and A. W. Weimer} } @article {1176, title = {Self-sustainable protonic ceramic electrochemical cells using a triple conducting electrode for hydrogen and power production}, journal = {Nature Communications}, volume = {11}, year = {2020}, month = {4}, keywords = {HTE; SOEC; Proton exchange membrane electrolysis cell; PrNi0.5Co0.5O3-δ perovskite}, doi = {10.1038/s41467-020-15677-z}, author = {Ding, Hanping and Wu, Wei and Jiang, Chao and Ding, Yong and Bian, Wenjuan and Hu, Boxun and Singh, Prabhakar and Orme, Christopher J. and Wang, Lucun and Zhang, Yunya and Ding, Dong} } @article {1179, title = {Understanding of A-site deficiency in layered perovskites: promotion of dual reaction kinetics for water oxidation and oxygen reduction in protonic ceramic electrochemical cells}, journal = {J. Mater. Chem. A}, volume = {8}, year = {2020}, pages = {14600-14608}, abstract = {Protonic ceramic electrochemical cells (PCECs) are promising solid-state energy conversion devices which enable the conversion of energy between electricity and hydrogen at intermediate temperatures. Rapid conversion between chemical and electrical energy via PCEC technology will assist in overcoming grand challenges in energy storage. To achieve highly efficient reversible operation between hydrogen production and electricity generation, boosting water-oxidation and oxygen reduction activities of the oxygen electrode while maintaining the durable operation is one of the early-stage technical opportunities. In this study, an A-site deficient layered perovskite (PrBa0.8Ca0.2)0.95Co2O6-δ has been developed as an oxygen electrode for a PCEC which presents superior electrochemical performances. The electrolysis current density reached as high as -0.72 A cm-2 at 1.3 V, and a peak power density of 0.540 W cm-2 was obtained at 600 {\textdegree}C in electrolysis and fuel cell mode, respectively. The PCEC with the new electrode shows good durability under practical operating conditions for 160 hours in both operating modes with no observable degradation. The reversibility between the electrolysis and fuel cell mode is also successfully demonstrated.}, keywords = {Durability; HTE; Layered perovskite; Protonic ceramic electrochemical cells}, doi = {10.1039/D0TA05137C}, url = {http://dx.doi.org/10.1039/D0TA05137C}, author = {Tang, Wei and Ding, Hanping and Bian, Wenjuan and Wu, Wei and Li, Wenyuan and Liu, Xingbo and Gomez, Joshua Y. and Regalado Vera, Clarita Y. and Zhou, Meng and Ding, Dong} } @article {1181, title = {Advancement of Proton-Conducting Solid Oxide Fuel Cells and Solid Oxide Electrolysis Cells at Idaho National Laboratory (INL)}, journal = {ECS Transactions}, volume = {91}, year = {2019}, month = {07/2019}, pages = {1029{\textendash}1034}, abstract = {Proton conducting ceramics have been considered as a strategic material system used in solid oxide fuel cells and solid oxide electrolysis cells for electricity generation and hydrogen production. The high proton conductivity of protonic electrolyte and rapid development of robust electrode materials have significantly promoted the reduction of feasible operating temperature to intermediate temperature range (400 600 {\textdegree}C), which can attribute to favorable technical and economic advantages when they are compared with conventional oxide-ion conducting electrolyte based solid oxide cell system. In the past few years, Idaho National Laboratory has been devoted to developing advanced electrolyte and electrode materials R\&D, diverse manufacturing capability, and expanding evaluation facility for these applications, aiming to further improve performance, stability and manufacturing cost. There are some remarkable accomplishments achieved on electrode engineering, electrolyte optimization, new material down-selection and large-scale cell fabrication in Idaho National Laboratory.}, keywords = {BCZYYb7111, HTE, NiO-BaCe0.7Zr0.1Y0.1Yb0.1O3, PrBa0.5Sr0.5Co1.5Fe0.5O3, Protonic conductor, SOEC}, doi = {10.1149/09101.1029ecst}, url = {https://doi.org/10.1149/09101.1029ecst}, author = {Hanping Ding and Wei Wu and Dong Ding} } @article {1060, title = {Approaches for co-sintering metal-supported proton-conducting solid oxide cells with Ba(Zr,Ce,Y,Yb)O3-δ electrolyte}, journal = {International Journal of Hydrogen Energy}, volume = {44}, year = {2019}, month = {05/2019}, pages = {13768-13776}, abstract = {

Published on May 21st, 2019. Proton conducting oxide electrolyte materials could potentially lower the operating temperature of metal-supported solid oxide cells (MS-SOCs) to the intermediate range 400 to 600\ {\textdegree}C. The porous metal substrate provides the advantages of MS-SOCs such as high thermal and redox cycling tolerance, low-cost of structural materials, and mechanical ruggedness. In this work, the viability of co-sintering fabrication of metal-supported proton conducting solid oxide cells using BaZr1-x-yCexYyO3-δ (BZCY) is investigated. BZCY ceramics are sintered at 1450\ {\textdegree}C in reducing environment alone and supported on FeCr alloy metal support, and key characteristics such as Ba loss, sintering behavior, and chemical compatibility with metal support are determined. Critical challenges are identified for this fabrication approach, including: Contamination of the electrolyte with Si and Cr from the metal support, incomplete electrolyte sintering, and evaporation of electrolyte constituents. Various approaches to overcome these limitations are proposed, and preliminary assessment indicates that the use of barrier layers, low-Si-content stainless steel, and sintering aids warrant further development.

}, doi = {10.1016/j.ijhydene.2019.03.181}, url = {http://www.sciencedirect.com/science/article/pii/S0360319919312108}, author = {Ruofan Wang and Grace Y. Lay and Dong Ding and Tianli Zhu} } @article {1061, title = {Assessment of co-sintering as a fabrication approach for metal-supported proton-conducting solid oxide cells}, journal = {Solid State Ionics}, volume = {332}, year = {2019}, month = {04/2019}, pages = {25-33}, abstract = {

Published on April 1st, 2019. Proton conducting oxide electrolyte materials could potentially lower the operating temperature of metal-supported solid oxide cells (MS-SOCs) to the intermediate range 400 to 600 {\textdegree}C. The porous metal substrate provides the advantages of MS-SOCs such as high thermal and redox cycling tolerance, low-cost of structural materials, and mechanical ruggedness. In this work, viability of co-sintering fabrication of metal-supported proton conducting solid oxide cells is investigated. Candidate proton conducting oxides including perovskite oxides BaZr0.7Ce0.2Y0.1O3-δ, SrZr0.5Ce0.4Y0.1O3-δ, and Ba3Ca1.18Nb1.82O9-δ, pyrochlore oxides La1.95Ca0.05Zr2O7-δ and La2Ce2O7, and acceptor doped rare-earth ortho-niobate La0.99Ca0.01NbO4 are synthesized via solid state reactive or sol-gel methods. These ceramics are sintered at 1450 {\textdegree}C in reducing environment alone and supported on Fe-Cr alloy metal support, and their key characteristics such as phase formation, sintering property, and chemical compatibility with metal support are determined. Most electrolyte candidates suffer from one or more challenges identified for this fabrication approach, including: phase decomposition in reducing atmosphere, evaporation of electrolyte constituents, contamination of the electrolyte with Si and Cr from the metal support, and incomplete electrolyte sintering. In contrast, La0.99Ca0.01NbO4 is found to be highly compatible with the metal support and co-sintering processing in reducing atmosphere. A metal-supported cell is fabricated with La0.99Ca0.01NbO4 electrolyte, ferritic stainless steel support, Pt air electrode and nanoparticulate ceria-Ni hydrogen electrocatalyst. The total resistance is 50 Ω{\textperiodcentered}cm2 at 600 {\textdegree}C. This work clearly demonstrates the challenges, opportunities, and breakthrough of metal-supported proton-conducting solid oxide cells by co-sintering fabrication.

}, issn = {0167-2738}, doi = {10.1016/j.ssi.2019.01.004}, url = {http://www.sciencedirect.com/science/article/pii/S0167273818309263}, author = {Ruofan Wang and Conor Byrne and Michael C. Tucker} } @article {1082, title = {Catalysts in electro-, photo- and photoelectrocatalytic CO2 reduction reactions}, journal = {Journal of Photochemistry and Photobiology C: Photochemistry Reviews}, year = {2019}, abstract = {

Published on March 2nd, 2019. Carbon dioxide (CO2) is regarded as a main contributor to the greenhouse effect. As a potential strategy to mitigate its negative impacts, the reduction of CO2 is environmentally critical, economically meaningful and scientifically challenging. Being both thermodynamically and kinetically unfavored, CO2 reduction requires catalysts as a crucial component irrespective of the reaction modes, be it electrocatalytic, photoelectrocatalytic or photocatalytic. In an effort to systematically review the types of catalysts that have been studied for CO2 reduction, we categorize them into two major groups: those being activated by external sources and those being photoexcited and activated themselves. Attention is focused on the detailed mechanisms for each group by which the reduction of CO2 proceeds, yielding a summary of the guiding principles for catalyst designs. This review highlights the importance of mechanistic studies, which permits us to discuss our perspectives on potential directions of catalyst investigation for future catalytic CO2 reduction research.

}, issn = {1389-5567}, doi = {10.1016/j.jphotochemrev.2019.02.002}, url = {http://www.sciencedirect.com/science/article/pii/S1389556718300674}, author = {Yawen Wang and Da He and Hongyu Chen and Dunwei Wang} } @article {1096, title = {Continuous on-sun solar thermochemical hydrogen production via an isothermal redox cycle}, journal = {Applied Energy}, volume = {249}, year = {2019}, month = {09/2019}, pages = {368-376}, abstract = {

Published in September 2019.

}, issn = {03062619}, doi = {10.1016/j.apenergy.2019.04.169}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0306261919308293}, author = {Amanda L. Hoskins and Samantha L. Millican and Caitlin E. Czernik and Ibraheam Alshankiti and Judy C. Netter and Timothy J. Wendelin and Charles B. Musgrave and Alan W. Weimer} } @article {1084, title = {Dependence of interface energetics and kinetics on catalyst loading in a photoelectrochemical system}, journal = {Nano Research}, year = {2019}, abstract = {

Published on March 11th, 2019. Solar hydrogen production by the photoelectrochemical method promises a means to store solar energy. While it is generally understood that the process is highly sensitive to the nature of the interface between the semiconductor and the electrolyte, a detailed understanding of this interface is still missing. For instance, few prior studies have established a clear relationship between the interface energetics and the catalyst loading amount. Here we aim to study this relationship on a prototypical Si-based photoelectrochemical system. Two types of interfaces were examined, one with GaN nanowires as a protection layer and one without. It was found that when GaN was present, higher Pt loading (\> 0.1 μg/cm2) led to not only better water reduction (and, hence, hydrogen evolution) kinetics but also more favorable interface energetics for greater photovoltages. In the absence of the protection layer, by stark contrast, increased Pt loading exhibited no measurable influence on the interface energetics, and the main difference was observed only in the hydrogen evolution kinetics. The study sheds new light on the importance of interface engineering for further improvement of photoelectrochemical systems, especially concerning the role of catalysts and protection layers.

}, issn = {1998-0000}, doi = {10.1007/s12274-019-2346-3}, url = {https://doi.org/10.1007/s12274-019-2346-3}, author = {Yumin He and Srinivas Vanka and Tianyue Gao and Da He and Jeremy Espano and Yanyan Zhao and Qi Dong and Chaochao Lang and Yongjie Wang and Thomas W. Hamann and Zetian Mi and Dunwei Wang} } @article {1183, title = {Direct Deposition of Crystalline Ta3N5 Thin Films on FTO for PEC Water Splitting}, journal = {ACS Applied Materials \& Interfaces}, volume = {11}, year = {2019}, pages = {15457-15466}, keywords = {ALD, CVD, FTO, PEC, Photoanode, Ta3N5, Tantalum nitride}, doi = {10.1021/acsami.8b21194}, url = {https://doi.org/10.1021/acsami.8b21194}, author = {Hajibabaei, Hamed and Little, Daniel J. and Pandey, Ayush and Wang, Dunwei and Mi, Zetian and Hamann, Thomas W.} } @article {1185, title = {Ferritic stainless steel interconnects for protonic ceramic electrochemical cell stacks: Oxidation behavior and protective coatings}, journal = {International Journal of Hydrogen Energy}, volume = {44}, year = {2019}, pages = {25297-25309}, abstract = {Protonic ceramic fuel or electrolysis cells (PCFC/PCEC) have shown promising performance at intermediate temperatures. However, these technologies have not yet been demonstrated in a stack, hence the oxidation behavior of the metallic interconnect under relevant operating environments is unknown. In this work, ferritic stainless steels 430 SS, 441 SS, and Crofer 22 APU were investigated for their use as interconnect materials in the PCFC/PCEC stack. The bare metal sheets were exposed to a humidified air environment in the temperature range from 450~{\textdegree}C to 650~{\textdegree}C, to simulate their application in a PCFC cathode or PCEC anode. Breakaway oxidation with rapid weight gain and Fe outward diffusion/oxidation was observed on all the selected stainless steel materials. A protective coating is deemed necessary to prevent the metallic interconnect from oxidizing. To mitigate the observed breakaway oxidation, state-of-the-art protective coatings, Y2O3, Ce0.02Mn1.49Co1.49O4, CuMn1.8O4 and Ce/Co, were applied to the stainless steel sheets and their oxidation resistance was investigated. Dual atmosphere testing further validated the effectiveness of the protective coatings in realistic PCFC/PCEC environments, with a hydrogen gradient across the interconnect. Several combinations of metal and coating material were found to be viable for use as the interconnect for PCFC/PCEC stacks.}, keywords = {Dual atmosphere, Interconnect oxidation, Oxidation, Protective coatings, Protonic ceramic electrolysis cell, Protonic ceramic fuel cell}, issn = {0360-3199}, doi = {https://doi.org/10.1016/j.ijhydene.2019.08.041}, url = {https://www.sciencedirect.com/science/article/pii/S0360319919329581}, author = {Ruofan Wang and Zhihao Sun and Jung-Pyung Choi and Soumendra N. Basu and Jeffry W. Stevenson and Michael C. Tucker} } @inbook {1073, title = {HydroGEN Overview: A Consortium on Advanced Water Splitting Materials (AWSM)}, booktitle = {FY 2018 DOE Hydrogen and Fuel Cells Program Annual Progress Report}, year = {2019}, author = {Huyen N. Dinh and R Boardman and A.H. McDaniel and H Colon-Mercado and T. Ogitsu and A.Z. Weber} } @article {1081, title = {An In0.42Ga0.58N tunnel junction nanowire photocathode monolithically integrated on a nonplanar Si wafer}, journal = {Nano Energy}, volume = {57}, year = {2019}, pages = {405-413}, abstract = {

Published on March 1st, 2019. Group III-nitride semiconductors exhibit many ideal characteristics for solar water splitting, including a tunable energy bandgap across nearly the entire solar spectrum and suitable band edge positions for water oxidation and proton reduction under visible and near-infrared light irradiation. To date, however, the best reported energy conversion efficiency for III-nitride semiconductor photocathodes is still below 1\%. Here we report on the demonstration of a relatively efficient p-type In0.42Ga0.58N photocathode, which is monolithically integrated on an n-type nonplanar Si wafer through a GaN nanowire tunnel junction. The open pillar design, together with the nonplanar Si wafer can significantly maximize light trapping, whereas the tunnel junction reduces the interfacial resistance and enhances the extraction of photo-generated electrons. In addition, photodeposited Pt nanoparticles on InGaN nanowire surfaces significantly improve the cathodic performance. The nanowire photocathode exhibits a photocurrent density of 12.3 mA cm-2 at 0 V vs. RHE and an onset potential of 0.79 V vs. RHE under AM 1.5 G one-sun illumination. The maximum applied bias photon-to-current efficiency reaches 4\% at ~0.52 V vs. RHE, which is one order of magnitude higher than the previously reported values for III-nitride photocathodes. Significantly, no performance degradation was measured for over 30 h solar water splitting with a steady photocurrent density ~12 mA cm-2 without using any extra surface protection, which is attributed to the spontaneous formation of N-terminated surfaces of InGaN nanowires to protect against photocorrosion.

}, issn = {2211-2855}, doi = {10.1016/j.nanoen.2018.12.067}, url = {http://www.sciencedirect.com/science/article/pii/S2211285518309807}, author = {Yongjie Wang and Srinivas Vanka and Jiseok Gim and Yuanpeng Wu and Ronglei Fan and Yazhou Zhang and Jinwen Shi and Mingrong Shen and Robert Hovden and Zetian Mi} } @article {796, title = {Integrated Membrane-Electrode-Assembly Photoelectrochemical Cell under Various Feed Conditions for Solar Water Splitting}, journal = {Journal of The Electrochemical Society}, volume = {166}, year = {2019}, note = {

{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n\ \n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright}

}, pages = {H3020-H3028}, issn = {0013-4651, 1945-7111}, doi = {10.1149/2.0041905jes}, url = {http://jes.ecsdl.org/lookup/doi/10.1149/2.0041905jes}, author = {Tobias A. Kistler and David Larson and Karl Walczak and Peter Agbo and Ian D. Sharp and Adam Z. Weber and Nemanja Danilovic} } @article {1066, title = {Interfacial Analysis of PEM Electrolyzer Using X-ray Computed Tomography}, journal = {Sustainable Energy \& Fuels}, year = {2019}, doi = {10.1039/C9SE00364A}, url = {https://pubs.rsc.org/en/content/articlelanding/2019/se/c9se00364a}, author = {Emily Leonard and Andrew D.~Shum and Nemaja Danilovic and Christopher Capuano and Katherine E.~Ayers and Lalit Pant and Adam Z Weber and Xianghui Xiao and Dilworth Parkinson and Iryna V~Zenyuk} } @article {1189, title = {Metal-Supported Solid Oxide Electrolysis Cell with Significantly Enhanced Catalysis}, journal = {Energy Technology}, volume = {7}, year = {2019}, pages = {1801154}, abstract = {High-temperature electrolysis (HTE) using solid oxide electrolysis cells (SOECs) is a promising hydrogen production technology and has attracted substantial research attention over the last decade. While most studies are conducted on hydrogen electrode-supported type cells, SOEC operation using metal-supported cells has received minimal attention. The development of metal-supported SOECs with performance similar to the best conventional SOECs is reported. These cells have stainless steel supports on both sides, 10Sc1CeSZ electrolyte and electrode backbones, and nano-structured catalysts infiltrated on both hydrogen and oxygen electrode sides. Samarium-doped ceria (SDC) mixed with Ni is infiltrated as a hydrogen electrode catalyst, and the effect of ceria:Ni ratio is studied. On the oxygen electrode side, catalysts including lanthanum strontium manganite (LSM), lanthanum strontium cobalt ferrite (LSCF), praseodymium oxide (Pr6O11), and their composite catalysts with SDC (i.e., LSM-SDC, LSCF-SDC, and Pr6O11-SDC) are compared. Using the materials with highest catalytic activity (Pr6O11-SDC and SDC40-Ni60) and optimizing the catalyst infiltration processes, excellent electrolysis performance of metal-supported cells is achieved. Current densities of -5.31, -4.09, -2.64, and -1.62 A cm-2 are achieved at 1.3 V and 50 vol\% steam content at 800, 750, 700, and 650 {\textdegree}C, respectively.}, keywords = {high-temperature steam electrolysis, Hydrogen production, infiltration, solid oxide electrolysis, solid oxide electrolyzer cells}, doi = {https://doi.org/10.1002/ente.201801154}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/ente.201801154}, author = {Wang, Ruofan and Dogdibegovic, Emir and Lau, Grace Y. and Tucker, Michael C.} } @article {1089, title = {Molybdenum Disulfide Catalytic Coatings via Atomic Layer Deposition for Solar Hydrogen Production from Copper Gallium Diselenide Photocathodes}, journal = {ACS Applied Energy Materials}, volume = {2}, year = {2019}, pages = {1060-1066}, abstract = {

We demonstrate that applying atomic layer deposition-derived molybdenum disulfide (MoS2) catalytic coatings on copper gallium diselenide (CGSe) thin film absorbers can lead to efficient wide band gap photocathodes for photoelectrochemical hydrogen production. We have prepared a device that is free of precious metals, employing a CGSe absorber and a cadmium sulfide (CdS) buffer layer, a titanium dioxide (TiO2) interfacial layer, and a MoS2 catalytic layer. The resulting MoS2/TiO2/CdS/CGSe photocathode exhibits a photocurrent onset of +0.53 V vs RHE and a saturation photocurrent density of -10 mA cm{\textendash}2, with stable operation for \>5 h in acidic electrolyte. Spectroscopic investigations of this device architecture indicate that overlayer degradation occurs inhomogeneously, ultimately exposing the underlying CGSe absorber.

}, doi = {10.1021/acsaem.8b01562}, url = {https://doi.org/10.1021/acsaem.8b01562}, author = {Thomas R. Hellstern and David W. Palm and James Carter and Alex D. DeAngelis and Kimberly Horsley and Lothar Weinhardt and Wanli Yang and Monika Blum and Nicolas Gaillard and Clemens Heske and Thomas F. Jaramillo} } @article {1075, title = {Phase Identification of the Layered Perovskite CexSr2{\textendash}xMnO4 and Application for Solar Thermochemical Water Splitting}, journal = {Inorganic Chemistry}, volume = {58}, year = {2019}, pages = {7705-7714}, abstract = {

Published on June 17th, 2019. Ruddlesden{\textendash}Popper (layered perovskite) phases are attracting significant interest because of their unique potential for many applications requiring mixed ionic and electronic conductivity. Here we report a new, previously undiscovered layered perovskite of composition, CexSr2{\textendash}xMnO4 (x = 0.1, 0.2, and 0.3). Furthermore, we demonstrate that this new system is suitable for solar thermochemical hydrogen production (STCH). Synchrotron radiation X-ray diffraction and transmission electron microscopy are performed to characterize this new system. Density functional theory calculations of phase stability and oxygen vacancy formation energy (1.76, 2.24, and 2.66 eV/O atom, respectively with increasing Ce content) reinforce the potential of this phase for STCH application. Experimental hydrogen production results show that this materials system produces 2{\textendash}3 times more hydrogen than the benchmark STCH oxide ceria at a reduction temperature of 1400 {\textdegree}C and an oxidation temperature of 1000 {\textdegree}C.

}, issn = {0020-1669}, doi = {10.1021/acs.inorgchem.8b03487}, url = {https://doi.org/10.1021/acs.inorgchem.8b03487}, author = {Debora R. Barcellos and Francisco G. Coury and Antoine Emery and Michael Sanders and Jianhua Tong and Anthony McDaniel and Christopher Wolverton and Michael Kaufman and Ryan O{\textquoteright}Hayre} } @article {1191, title = {Progress in Metal-Supported Solid Oxide Fuel Cells and Electrolyzers with Symmetric Metal Supports and Infiltrated Electrodes}, journal = {ECS Transactions}, volume = {91}, year = {2019}, month = {07/2019}, pages = {877{\textendash}885}, abstract = {The LBNL metal-supported solid oxide cell architecture contains zirconia electrolyte and porous backbones co-sintered between porous stainless steel supports. Advantages of this design include low-cost structural materials, mechanical ruggedness, excellent tolerance to redox cycling, and extremely fast start-up capability. With infiltrated catalysts, high performance is also achieved: 1.5 W/cm2 with hydrogen fuel and 1.3 W/cm2 with internal reforming of ethanol fuel at 700 {\textdegree}C; 2.6 A/cm2 electrolysis current density at 1.3V and 50\% steam/50\% hydrogen at 700{\textdegree}C. Recent approaches to mitigating catalyst coarsening and Cr deposition within the cathode stabilize the microstructure during operation. The degradation rate is improved to 2.3\% kh-1 at 700{\textdegree}C in fuel cell mode. Electrolysis operation, however, results in higher degradation rate. Preliminary effort to fabricate metal-supported cells with proton conducting electrolyte is successful for La0.99Ca0.01NbO4 electrolyte, and specific challenges for BaZr0.7Ce0.2Y0.1O3-δ electrolyte are determined.}, keywords = {BaZr0.7Ce0.2Y0.1O3-δ electrolyte, HTE, La0.99Ca0.01NbO4 electrolyte, SOEC}, doi = {10.1149/09101.0877ecst}, url = {https://doi.org/10.1149/09101.0877ecst}, author = {Emir Dogdibegovic and Fengyu Shen and Ruofan Wang and Ian Robinson and Grace Y Lau and Michael C Tucker} } @article {1078, title = {The role of decomposition reactions in assessing first-principles predictions of solid stability}, journal = {npj Computational Materials}, volume = {5}, year = {2019}, pages = {4}, abstract = {

Published on January 4th, 2019. The performance of density functional theory approximations for predicting materials thermodynamics is typically assessed by comparing calculated and experimentally determined enthalpies of formation from elemental phases, ΔHf. However, a compound competes thermodynamically with both other compounds and their constituent elemental forms, and thus, the enthalpies of the decomposition reactions to these competing phases, ΔHd, determine thermodynamic stability. We evaluated the phase diagrams for 56,791 compounds to classify decomposition reactions into three types: 1. those that produce elemental phases, 2. those that produce compounds, and 3. those that produce both. This analysis shows that the decomposition into elemental forms is rarely the competing reaction that determines compound stability and that approximately two-thirds of decomposition reactions involve no elemental phases. Using experimentally reported formation enthalpies for 1012 solid compounds, we assess the accuracy of the generalized gradient approximation (GGA) (PBE) and meta-GGA (SCAN) density functionals for predicting compound stability. For 646 decomposition reactions that are not trivially the formation reaction, PBE (mean absolute difference between theory and experiment (MAD)\ =\ 70\ meV/atom) and SCAN (MAD\ =\ 59\ meV/atom) perform similarly, and commonly employed correction schemes using fitted elemental reference energies make only a negligible improvement (~2 meV/atom). Furthermore, for 231 reactions involving only compounds (Type 2), the agreement between SCAN, PBE, and experiment is within ~35\ meV/atom and is thus comparable to the magnitude of experimental uncertainty.

}, issn = {2057-3960}, doi = {10.1038/s41524-018-0143-2}, url = {https://www.nature.com/articles/s41524-018-0143-2}, author = {Christopher J. Bartel and Alan W. Weimer and Stephan Lany and Charles B. Musgrave and Aaron M. Holder} } @article {1093, title = {A Single-Junction Cathodic Approach for Stable Unassisted Solar Water Splitting}, journal = {Joule}, year = {2019}, abstract = {

Published in August 2019.

}, issn = {25424351}, doi = {10.1016/j.joule.2019.07.022}, url = {https://linkinghub.elsevier.com/retrieve/pii/S2542435119303666}, author = {Yongjie Wang and Yuanpeng Wu and Jonathan Schwartz and Suk Hyun Sung and Robert Hovden and Zetian Mi} } @article {1192, title = {Stable Unassisted Solar Water Splitting on Semiconductor Photocathodes Protected by Multifunctional GaN Nanostructures}, journal = {ACS Energy Letters}, volume = {4}, year = {2019}, pages = {1541-1548}, keywords = {durability, GaAs, GaInP2, GaN nanowires, Ge, III-V, PEC, Photocathode, Unbiased water splitting}, doi = {10.1021/acsenergylett.9b00549}, url = {https://doi.org/10.1021/acsenergylett.9b00549}, author = {Wang, Yongjie and Schwartz, Jonathan and Gim, Jiseok and Hovden, Robert and Mi, Zetian} } @article {1090, title = {Thin film photoelectrodes for solar water splitting}, journal = {Chemical Society Reviews}, volume = {48}, year = {2019}, pages = {2182-2215}, abstract = {

Published on April 1st, 2019. Photoelectrochemical (PEC) water splitting has been intensively studied in the past decades as a promising method for large-scale solar energy storage. Among the various issues that limit the progress of this field, the lack of photoelectrode materials with suitable properties in all aspects of light absorption, charge separation and transport, and charge transfer is a key challenge, which has attracted tremendous research attention. A large variety of compositions, in different forms, have been tested. This review aims to summarize efforts in this area, with a focus on materials-related considerations. Issues discussed by this review include synthesis, optoelectronic properties, charge behaviors and catalysis. In the recognition that thin-film materials are representative model systems for the study of these issues, we elected to focus on this form, so as to provide a concise and coherent account on the different strategies that have been proposed and tested. Because practical implementation is of paramount importance to the eventual realization of using solar fuel for solar energy storage, we pay particular attention to strategies proposed to address the stability and catalytic issues, which are two key factors limiting the implementation of efficient photoelectrode materials. To keep the overall discussion focused, all discussions were presented within the context of water splitting reactions. How the thin-film systems may be applied for fundamental studies of the water splitting chemical mechanisms and how to use the model system to test device engineering design strategies are discussed.

}, issn = {1460-4744}, doi = {10.1039/C8CS00868J}, url = {https://pubs.rsc.org/en/content/articlelanding/2019/cs/c8cs00868j}, author = {Yumin He and Thomas Hamann and Dunwei Wang} } @article {1062, title = {Cobalt-substituted SrTi0.3Fe0.7O3-δ: a stable high-performance oxygen electrode material for intermediate-temperature solid oxide electrochemical cells}, journal = {Energy \& Environmental Science}, volume = {11}, year = {2018}, month = {07/2018}, pages = {1870-1879}, abstract = {

Published on July 11th, 2018. A key need in the development of solid oxide cells (SOCs) is for electrodes that promote fast oxygen reduction and oxygen evolution reactions at reduced operating temperature (<=700 {\textdegree}C), with sufficient durability to allow operation over desired 40 000 h lifetimes. A wide range of electrode materials have been investigated, with some providing resistance low enough for cell operation below 700 {\textdegree}C, but it is generally found that the electrode performance degrades over time. Here we demonstrate an oxygen electrode material, Sr(Ti0.3Fe0.7-xCox)O3-δ (STFC), that provides a unique combination of excellent oxygen electrode performance and long-term stability. The addition of a relatively small amount of Co to Sr(Ti0.3Fe0.7)O3-δ, e.g., x = 0.07, reduces the electrode polarization resistance by \>2 times. The STFC electrode yields stable performance in both fuel cell and electrolysis modes at 1 A cm-2. The fundamental oxygen diffusion and surface exchange coefficients of STFC are determined, and shown to be substantially better than those of La0.6Sr0.4Co0.2Fe0.8O3-δ, the most widely used SOC oxygen electrode material. While other electrode materials have been shown to exhibit better oxygen transport coefficients than STFC, they do not match its stability.

}, doi = {10.1039/C8EE00449H}, url = {https://pubs.rsc.org/en/content/articlelanding/2018/ee/c8ee00449h}, author = {Shan-Lin Zhang and Hongqian Wang and Matthew Y. Lu and Ai-Ping Zhang and Liliana V. Mogni and Qinyuan Liu and Cheng-Xin Li and Chang-Jiu Li and Scott A. Barnett} } @article {1085, title = {Gallium nitride nanowire as a linker of molybdenum sulfides and silicon for photoelectrocatalytic water splitting}, journal = {Nature Communications}, volume = {9}, year = {2018}, month = {09/2018}, pages = {3856}, abstract = {

Published on September 21st, 2018. Sunlight-harvesting materials require the clean integration of light-absorbing and catalytic components to be efficient. Here, authors link silicon photoelectrodes and molybdenum sulfide catalysts with defect-free gallium nitride nanowire to improve photoelectrochemical hydrogen evolution.

}, issn = {2041-1723}, doi = {10.1038/s41467-018-06140-1}, url = {https://www.nature.com/articles/s41467-018-06140-1}, author = {Baowen Zhou and Xianghua Kong and Srinivas Vanka and Sheng Chu and Pegah Ghamari and Yichen Wang and Nick Pant and Ishiang Shih and Hong Guo and Zetian Mi} } @article {1063, title = {Hydrogen Production: 3D Self-Architectured Steam Electrode Enabled Efficient and Durable Hydrogen Production in a Proton-Conducting Solid Oxide Electrolysis Cell at Temperatures Lower Than 600 {\textdegree}C (Adv. Sci. 11/2018)}, journal = {Advanced Science}, volume = {5}, year = {2018}, month = {2018}, pages = {1870070}, abstract = {

In article number 1800360, Dong Ding and co-workers report a self-architectured ultraporous 3D electrode for steam electrolysis at intermediate temperatures. The proton-conducting electrolysis cell using this steam electrode demonstrates highly efficient and durable hydrogen production below 600 {\textdegree}C, which is attributed to improved mass transfer and increased active reaction area, as well as the electrode reconstruction under operation conditions.

}, issn = {2198-3844}, doi = {10.1002/advs.201870070}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/advs.201870070}, author = {Wei Wu and Hanping Ding and Yunya Zhang and Yong Ding and Prashant Katiyar and Prasun K. Majumdar and Ting He and Dong Ding} } @article {1041, title = {Integrating Ab Initio Simulations and X-ray Photoelectron Spectroscopy: Toward A Realistic Description of Oxidized Solid/Liquid Interfaces}, journal = {The Journal of Physical Chemistry Letters}, volume = {9}, year = {2018}, note = {

{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n\ \n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright}

}, pages = {194-203}, abstract = {

Published on January 4th, 2019. Many energy storage and conversion devices rely on processes that take place at complex interfaces, where structural and chemical properties are often difficult to probe under operating conditions. A primary example is solar water splitting using high-performance photoelectrochemical cells, where surface chemistry, including native oxide formation, affects hydrogen generation. In this Perspective, we discuss some of the challenges associated with interrogating interface chemistry, and how they may be overcome by integrating high-level first-principles calculations of explicit interfaces with ambient pressure X-ray photoelectron spectroscopy and direct spectroscopic simulations. We illustrate the benefit of this combined approach toward insights into native oxide chemistry at prototypical InP/water and GaP/water interfaces. This example suggests a more general roadmap for obtaining a realistic and reliable description of the chemistry of complex interfaces by combining state-of-the-art computational and experimental techniques.

}, issn = {1948-7185}, doi = {10.1021/acs.jpclett.7b01382}, url = {https://doi.org/10.1021/acs.jpclett.7b01382}, author = {Tuan Anh Pham and Xueqiang Zhang and Brandon C. Wood and David Prendergast and Sylwia Ptasinska and Tadashi Ogitsu} } @article {1097, title = {(Invited) HydroGEN: An AWSM Energy Materials Network}, journal = {ECS Transactions}, volume = {85}, year = {2018}, month = {05/2018}, pages = {3-14}, abstract = {

The HydroGEN (https://www.h2awsm.org/) energy materials network (EMN) aims to accelerate the research and development (R\&D) of advanced water splitting (AWS) technologies for clean, sustainable hydrogen production. Announced in October 2016, the HydroGEN EMN comprises six core National Laboratories and focuses on four AWS pathways: low- and high-temperature electrolysis, photoelectrochemical, and solar thermochemical water splitting. The HydroGEN consortium offers an extensive collection of materials research capabilities for addressing R\&D challenges in discovery and design, efficacy and efficiency, durability and cost. Leveraging the HydroGEN Consortium{\textquoteright}s technical experts and broad collection of unique resource capabilities is expected to advance the maturity and technology readiness levels in each advanced water splitting technology pathway.

}, issn = {1938-6737, 1938-5862}, doi = {10.1149/08511.0003ecst}, url = {http://ecst.ecsdl.org/content/85/11/3}, author = {James W. Vickers and Huyen N. Dinh and Katie Randolph and Adam Z. Weber and Anthony H. McDaniel and Richard Boardman and Tadashi Ogitsu and Hector Colon-Mercado and David Peterson and Eric L. Miller} } @article {1088, title = {Metallic nanocatalysts for electrochemical CO2 reduction in aqueous solutions}, journal = {Journal of Colloid and Interface Science}, volume = {527}, year = {2018}, pages = {95-106}, abstract = {

Published on October 1st, 2018. How to effectively and efficiently reduce carbon dioxide (CO2) to value-added chemicals represent a frontier in catalysis research. Due to the high activation energy needs and the endothermic nature of CO2 reduction, the reactions are difficult to carry out. When H2O is present, hydrogen evolution reactions (HER) often compete favorably with CO2 reduction reactions. For these reactions, catalysts are of critical importance to CO2 reduction. In this article, we review the various metal nanocatalysts for electrochemical CO2 reduction (ECR) reactions. In recognition of the importance of H2O to CO2 reduction, we focus our discussions on systems in aqueous solutions. Nanostructured metal catalysts are chosen for the discussions because they represent the most effective catalysts for ECR. After a brief introduction of the fundamental principles of ECR, we devote the rest of the article on the discussions of various types of nanostructured metallic catalysts, which are categorized by their compositions and working mechanisms. Lastly, strategies for improving reaction efficiency and selectivity are discussed.

}, issn = {0021-9797}, doi = {10.1016/j.jcis.2018.05.041}, url = {http://www.sciencedirect.com/science/article/pii/S0021979718305538}, author = {Yuanxing Wang and Cailing Niu and Dunwei Wang} } @article {1076, title = {Physical descriptor for the Gibbs energy of inorganic crystalline solids and temperature-dependent materials chemistry}, journal = {Nature Communications}, volume = {9}, year = {2018}, month = {10/2018}, pages = {4168}, issn = {2041-1723}, doi = {10.1038/s41467-018-06682-4}, url = {https://www.nature.com/articles/s41467-018-06682-4}, author = {Christopher J. Bartel and Samantha L. Millican and Ann M. Deml and John R. Rumptz and William Tumas and Alan W. Weimer and Stephan Lany and Vladan Stevanovi{\'c} and Charles B. Musgrave and Aaron M. Holder} } @article {1077, title = {Solar Thermochemical Hydrogen (STCH) Processes}, journal = {The Electrochemical Society Interface}, volume = {27}, year = {2018}, pages = {53-56}, issn = {1064-8208, 1944-8783}, doi = {10.1149/2.F05181if}, url = {http://interface.ecsdl.org/lookup/doi/10.1149/2.F05181if}, author = {Maximilian B. Gorensek and Claudio Corgnale and John A. Staser and John W. Weidner} } @article {1042, title = {Solar Water Oxidation by an InGaN Nanowire Photoanode with a Bandgap of 1.7 eV}, journal = {ACS Energy Letters}, volume = {3}, year = {2018}, note = {

{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n\ \n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright}

}, pages = {307-314}, abstract = {

Published on February 9th, 2018. The performance of overall solar water splitting has been largely limited by the half-reaction of water oxidation. Here, we report a 1.7 eV bandgap InGaN nanowire photoanode for efficient solar water oxidation. It produces a low onset potential of 0.1 V versus a reversible hydrogen electrode (RHE) and a high photocurrent density of 5.2 mA/cm2 at a potential as low as 0.6 V versus RHE. The photoanode yields a half-cell solar energy conversion efficiency up to 3.6\%, a record for a single-photon photoanode to our knowledge. Furthermore, in the presence of hole scavengers, the photocurrent density of the InGaN photoanode reaches 21.2 mA/cm2 at 1.23 V versus RHE, which approaches the theoretical limit for a 1.7 eV InGaN absorber. The InGaN nanowire photoanode may serve as an ideal top cell in a photoelectrochemical tandem device when stacked with a 0.9{\textendash}1.2 eV bandgap bottom cell, which can potentially deliver solar-to-hydrogen efficiency over 25\%.

}, doi = {10.1021/acsenergylett.7b01138}, url = {https://doi.org/10.1021/acsenergylett.7b01138}, author = {Sheng Chu and Srinivas Vanka and Yichen Wang and Jiseok Gim and Yongjie Wang and Yong-Ho Ra and Robert Hovden and Hong Guo and Ishiang Shih and Zetian Mi} } @article {1091, title = {Toward Practical Solar Hydrogen Production}, journal = {Chem}, volume = {4}, year = {2018}, month = {03/2018}, pages = {405-408}, abstract = {

Published on March 8th, 2018. Two articles recently published in Joule represent efforts in material discovery and new engineering for practical solar hydrogen production. Wong and colleagues improved the solar hydrogen production performance of Cu2ZnSnS4 by Cd substitution, and Domen and co-workers presented a panel design to take advantage of particulate Al-doped SrTiO3 photocatalysts for overall water splitting.

}, issn = {2451-9294}, doi = {10.1016/j.chempr.2018.02.013}, url = {http://www.sciencedirect.com/science/article/pii/S2451929418300743}, author = {Yumin He and Dunwei Wang} } @article {1008, title = {Anodic Behavior of the Aluminum Current Collector in Imide-Based Electrolytes: Influence of Solvent, Operating Temperature, and Native Oxide-Layer Thickness}, journal = {ChemSusChem}, volume = {10}, year = {2017}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {804-814}, abstract = {Published on February 22nd, 2017. The inability of imide salts to form a sufficiently effective passivation layer on aluminum current collectors is one of the main obstacles that limit their broad application in electrochemical energy-storage systems. However, under certain circumstances, the use of electrolytes with imide electrolyte salts in combination with the aluminum current collector is possible. In this contribution, the stability of the aluminum current collector in electrolytes containing either lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) or lithium fluorosulfonyl-(trifluoromethanesulfonyl) imide (LiFTFSI) as conductive salt was investigated by electrochemical techniques, that is, cyclic voltammetry (CV) and chronocoulometry (CC) in either room-temperature ionic liquids or in ethyl methyl sulfone. In particular, the influence of the solvent, operating temperature, and thickness of the native oxide layer of aluminum on the pit formation at the aluminum current collector surface was studied by means of scanning electron microscopy. In general, a more pronounced aluminum dissolution and pit formation was found at elevated temperatures as well as in solvents with a high dielectric constant. An enhanced thickness of the native aluminum oxide layer increases the oxidative stability versus dissolution. Furthermore, we found a different reaction rate depending on dwell time at the upper cut-off potential for aluminum dissolution in TFSI- and FTFSI-based electrolytes during the CC measurements; the use of LiFTFSI facilitated the dissolution of aluminum compared to LiTFSI. Overall, the mechanism of anodic aluminum dissolution is based on: i) the attack of the Al2O3 surface by acidic species and ii) the dissolution of bare aluminum into the electrolyte, which, in turn, is influenced by the electrolyte{\textquoteright}s dielectric constant.}, issn = {1864-564X}, doi = {10.1002/cssc.201601636}, url = {http://onlinelibrary.wiley.com/doi/10.1002/cssc.201601636/abstract}, author = {Paul Meister and Xin Qi and Richard Kloepsch and Elisabeth Kr{\"a}mer and Benjamin Streipert and Martin Winter and Tobias Placke} } @article {801, title = {Characterizing Voltage Losses in an SO2 Depolarized Electrolyzer Using Sulfonated Polybenzimidazole Membranes}, journal = {Journal of The Electrochemical Society}, volume = {164}, year = {2017}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {F1591-F1595}, abstract = {Published on January 1st, 2017. The hybrid sulfur cycle has been investigated as a means to produce CO2-free hydrogen efficiently on a large scale through the decomposition of H2SO4 to SO2, O2, and H2O, and then electrochemically oxidizing SO2 back to H2SO4 with the cogeneration of H2. The net effect is the production of hydrogen and oxygen from water. Recently, sulfonated polybenzimidazoles (s-PBI) have been investigated as a replacement for Nafion due to the ability to offer increased process efficiency through the generation of higher acid concentrations at lower potentials. Here, we measure the acid concentrations and individual potential contributions toward the overall operating voltage seen in the SO2-depolarized-electrolyzer. We then determine model parameters necessary to predict voltage losses in a cell over a wide range of operating temperatures, pressures, currents and reactant flow rates.}, issn = {0013-4651, 1945-7111}, doi = {10.1149/2.1061714jes}, url = {http://jes.ecsdl.org/content/164/14/F1591}, author = {Taylor R. Garrick and Cody H. Wilkins and Andrew T. Pingitore and Jacob Mehlhoff and Alex Gulledge and Brian C. Benicewicz and John W. Weidner} } @article {823, title = {A novel CeO2{\textendash}xSnO2/Ce2Sn2O7 pyrochlore cycle for enhanced solar thermochemical water splitting}, journal = {AIChE Journal}, volume = {63}, year = {2017}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {3450-3462}, abstract = {Published in August 2017.}, issn = {00011541}, doi = {10.1002/aic.15701}, url = {http://doi.wiley.com/10.1002/aic.15701}, author = {Chongyan Ruan and Yuan Tan and Lin Li and Junhu Wang and Xiaoyan Liu and Xiaodong Wang} } @article {988, title = {Self-optimizing, highly surface-active layered metal dichalcogenide catalysts for hydrogen evolution}, journal = {Nature Energy}, volume = {6}, year = {2017}, note = {

{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n\ \n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright}

}, pages = {17127}, author = {Yuanyue Liu and Jingjie Wu and Ken P Hackenberg and Y. Morris Wang and Yingchao Yang and Kunttal Keyshar and Jing Gu and Tadashi Ogitsu and Robert Vajtai and Jun Lou and Pulickel M. Ajayan and Brandon C. Wood and Boris I. Yakobson} } @article {1011, title = {An analysis of degradation phenomena in polymer electrolyte membrane water electrolysis}, journal = {Journal of Power Sources}, volume = {326}, year = {2016}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {120-128}, abstract = {Published on September 15th, 2016. The durability of a polymer electrolyte membrane (PEM) water electrolysis single cell, assembled with regular porous transport layers (PTLs) is investigated for just over 1000~h. We observe a significant degradation rate of 194~μV~h-1 and conclude that 78\% of the detectable degradation can be explained by an increase in ohmic resistance, arising from the anodic Ti-PTL. Analysis of the polarization curves also indicates a decrease in the anodic exchange current density, j0, that results from the over-time contamination of the anode with Ti species. Furthermore, the average Pt-cathode particle size increases during the test, but we do not believe this phenomenon makes a significant contribution to increased cell voltages. To validate the anode Ti-PTL as a crucial source of increasing resistance, a second cell is assembled using Pt-coated Ti-PTLs. This yields a substantially reduced degradation rate of only 12~μV~h-1, indicating that a non-corroding anode PTL is vital for PEM electrolyzers. It is our hope that forthcoming tailored PTLs will not only contribute to fast progress on cost-efficient stacks, but also to its long-term application of PEM electrolyzers involved in industrial processes.}, issn = {0378-7753}, doi = {10.1016/j.jpowsour.2016.06.082}, url = {http://www.sciencedirect.com/science/article/pii/S0378775316307844}, author = {Christoph Rakousky and Uwe Reimer and Klaus Wippermann and Marcelo Carmo and Wiebke Lueke and Detlef Stolten} } @conference {862, title = {Design and construction of a cascading pressure reactor prototype for solar-thermochemical hydrogen production}, volume = {1734}, year = {2016}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {120001}, address = {Cape Town, South Africa}, doi = {10.1063/1.4949203}, url = {http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.4949203}, author = {Ivan Ermanoski and Johannes Grobbel and Abhishek Singh and Justin Lapp and Stefan Brendelberger and Martin Roeb and Christian Sattler and Josh Whaley and Anthony McDaniel and Nathan P. Siegel} } @article {821, title = {A review and perspective of efficient hydrogen generation via solar thermal water splitting}, journal = {Wiley Interdisciplinary Reviews: Energy and Environment}, volume = {5}, year = {2016}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {261-287}, abstract = {Published in May 2016.}, issn = {20418396}, doi = {10.1002/wene.174}, url = {http://doi.wiley.com/10.1002/wene.174}, author = {Christopher L. Muhich and Brian D. Ehrhart and Ibraheam Al-Shankiti and Barbara J. Ward and Charles B. Musgrave and Alan W. Weimer} } @article {773, title = {X-ray absorption study of ceria nanorods promoting the disproportionation of hydrogen peroxide}, journal = {ChemComm}, volume = {52}, year = {2016}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {5003-5006}, abstract = {A quasi in situ X-ray absorption study demonstrated that the disproportionation of hydrogen peroxide (H2O2) promoted by ceria nanorods was associated with a reversible Ce3+/Ce4+ reaction and structural transformations in ceria. The direction of this reversible reaction was postulated to depend on the H2O2 concentration and the fraction of Ce3+ species in ceria nanorods.}, doi = {10.1039/c5cc10643e}, author = {Wu Tai-Sing and Zhou Yunyun and Sabirianov Renat and Mei Wai-Ning and Soo Yun-Liang and Cheung Chin} } @article {861, title = {Predicting the solar thermochemical water splitting ability and reaction mechanism of metal oxides: a case study of the hercynite family of water splitting cycles}, journal = {Energy Environ. Sci.}, year = {2015}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, issn = {1754-5692, 1754-5706}, doi = {10.1039/C5EE01979F}, url = {http://xlink.rsc.org/?DOI=C5EE01979F}, author = {Christopher L. Muhich and Brian D. Ehrhart and Vanessa A. Witte and Samantha L. Miller and Eric N. Coker and Charles B. Musgrave and Alan W. Weimer} } @article {846, title = {CeO2 modified Fe2O3 for the chemical hydrogen storage and production via cyclic water splitting}, journal = {International Journal of Hydrogen Energy}, volume = {39}, year = {2014}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {13381-13388}, abstract = {Published in August 2014.}, issn = {03603199}, doi = {10.1016/j.ijhydene.2014.04.136}, url = {http://linkinghub.elsevier.com/retrieve/pii/S036031991401194X}, author = {Xing Zhu and Lingyue Sun and Yane Zheng and Hua Wang and Yonggang Wei and Kongzhai Li} } @article {933, title = {Kinetics and mechanism of solar-thermochemical H2 production by oxidation of a cobalt ferrite{\textendash}zirconia composite}, journal = {Energy \& Environmental Science}, volume = {6}, year = {2013}, note = {

{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n\ \n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright}

}, pages = {963}, issn = {1754-5692, 1754-5706}, doi = {10.1039/c3ee23568h}, url = {http://xlink.rsc.org/?DOI=c3ee23568h}, author = {Jonathan R. Scheffe and Anthony H. McDaniel and Mark D. Allendorf and Alan W. Weimer} } @article {815, title = {Atomic layer deposited thin film metal oxides for fuel production in a solar cavity reactor}, journal = {International Journal of Hydrogen Energy}, volume = {37}, year = {2012}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {16888-16894}, abstract = {Published in November 2012.}, issn = {03603199}, doi = {10.1016/j.ijhydene.2012.08.004}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0360319912017703}, author = {Paul Lichty and Xinhua Liang and Christopher Muhich and Brian Evanko and Carl Bingham and Alan W. Weimer} } @article {898, title = {CoFe2O4 on a Porous Al2O3 Nanostructure for Solar Thermochemical CO2 Splitting}, journal = {Energy \& Environmental Science}, volume = {5}, year = {2012}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {9438-9444}, issn = {1754-5692, 1754-5706}, doi = {10.1039/c2ee22090c}, url = {http://xlink.rsc.org/?DOI=c2ee22090c}, author = {Darwin Arifin and Victoria J. Aston and Xinhua Liang and Anthony H. McDaniel and Alan W. Weimer} } @article {819, title = {A Spinel Ferrite/Hercynite Water-Splitting Redox Cycle}, journal = {International Journal of Hydrogen Energy}, volume = {35}, year = {2010}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {3333-3340}, abstract = {Published in April 2010.}, issn = {03603199}, doi = {10.1016/j.ijhydene.2010.01.140}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0360319910002387}, author = {Jonathan R. Scheffe and Jianhua Li and Alan W. Weimer} } @article {1134, title = {Assessing the Oxidative Stability of Anion Exchange Membranes in Oxygen Saturated Aqueous Alkaline Solutions}, journal = {Frontiers in Energy Research}, volume = {10}, month = {2022}, keywords = {anion exchange membrane, conductivity, electrolysis, protocol and guidelines, stability}, doi = {10.3389/fenrg.2022.871851}, author = {Arges, Christopher G. and Ramani, Vijay and Wang, Zhongyang and Ouimet, Ryan J.} } @article {751, title = {Defect engineering by synchrotron radiation X-rays in CeO2 nanocrystals}, journal = {Journal of Synchrotron Radiation}, volume = {25}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {1395-1399}, abstract = {This work reports an unconventional defect engineering approach using synchrotron-radiation-based X-rays on ceria nanocrystal catalysts of particle sizes 4.4-10.6nm. The generation of a large number of oxygen-vacancy defects (OVDs), and therefore an effective reduction of cations, has been found in CeO2 catalytic materials bombarded by high-intensity synchrotron X-ray beams of beam size 1.5mmx0.5mm, photon energies of 5.5-7.8keV and photon fluxes up to 1.53x10(12) photons s(-1). The experimentally observed cation reduction was theoretically explained by a first-principles formation-energy calculation for oxygen vacancy defects. The results clearly indicate that OVD formation is mainly a result of X-ray-excited core holes that give rise to valence holes through electron down conversion in the material. Thermal annealing and subvalent Y-doping were also employed to modulate the efficiency of oxygen escape, providing extra control on the X-ray-induced OVD generating process. Both the core-hole-dominated bond breaking and oxygen escape mechanisms play pivotal roles for efficient OVD formation. This X-ray irradiation approach, as an alternative defect engineering method, can be applied to a wide variety of nanostructured materials for physical-property modification.}, issn = {1600-5775}, doi = {10.1107/S1600577518008184}, author = {Tai-Sing Wu and Leng-You Syu and Shih-Chang Weng and Horng-Tay Jeng and Shih-Lin Chang and Yun-Liang Soo} } @article {1020, title = {Durable Membrane Electrode Assemblies for Proton Exchange Membrane Electrolyzer Systems Operating at High Current Densities}, journal = {Electrochimica Acta}, volume = {210}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {502-511}, abstract = {High efficiencies, wide operation range and rapid response time have motivated the recent interest in proton exchange membrane (PEM) electrolysis for hydrogen generation with surplus electricity. However, degradation at high current densities and the associated mechanism has not been thoroughly explored so far. In this work, membrane electrode assemblies (MEA) from different suppliers are aged in a commercial PEM electrolyzer (2.5Nm3H2h--1), operating up to 4Acm--2 for more than 750h. In all cases, the cell voltage (Ecell) decreases during the testing period. Interestingly, the cells with Ir-black anodes exhibit the highest performance with the lowest precious metal loading (1mgcm-2). Electrochemical impedance spectroscopy (EIS) shows a progressive decrease in the specific exchange current, while the ohmic resistance decreases when doubling the nominal current density. This effect translates into an enhancement of cell efficiency at high current densities. However, Ir concurrently leaches out and diffuses into the membrane. No decrease in membrane thickness is observed at the end of the tests. High current densities do not lead to lowering the performance of the PEM electrolyzer over time, although MEA components degrade, in particular the anode.}, issn = {0013-4686}, doi = {10.1016/j.electacta.2016.04.164}, url = {http://www.sciencedirect.com/science/article/pii/S0013468616310167}, author = {P. Lettenmeier and R. Wang and R. Abouatallah and S. Helmly and T. Morawietz and R. Hiesgen and S. Kolb and F. Burggraf and J. Kallo and A. S. Gago and K. A. Friedrich} } @article {930, title = {Efficient generation of H2 by splitting water with an isothermal redox cycle}, journal = {Science}, volume = {341}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {540-542}, issn = {0036-8075, 1095-9203}, doi = {10.1126/science.1239454}, url = {http://www.sciencemag.org/cgi/doi/10.1126/science.1239454}, author = {C. L. Muhich and B. W. Evanko and K. C. Weston and P. Lichty and X. Liang and J. Martinek and C. B. Musgrave and A. W. Weimer} } @article {971, title = {Experimental demonstration of the thermochemical reduction of ceria in a solar aerosol reactor}, journal = {Industrial \& Engineering Chemistry Research}, volume = {55}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {10618-10625}, issn = {0888-5885, 1520-5045}, doi = {10.1021/acs.iecr.6b02853}, url = {http://pubs.acs.org/doi/abs/10.1021/acs.iecr.6b02853}, author = {Michael Welte and Rafik Barhoumi and Adrian Zbinden and Jonathan R. Scheffe and Aldo Steinfeld} } @article {964, title = {Extracting kinetic information from complex gas{\textendash}solid reaction data}, journal = {Industrial \& Engineering Chemistry Research}, volume = {54}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {4113-4122}, issn = {0888-5885, 1520-5045}, doi = {10.1021/ie503894f}, url = {http://pubs.acs.org/doi/abs/10.1021/ie503894f}, author = {Christopher L. Muhich and Kayla C. Weston and Darwin Arifin and Anthony H. McDaniel and Charles B. Musgrave and Alan W. Weimer} } @article {893, title = {First-principles thermodynamic framework for the evaluation of thermochemical H2O- or CO2-splitting materials}, journal = {Physical Review B}, volume = {80}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, issn = {1098-0121, 1550-235X}, doi = {10.1103/PhysRevB.80.245119}, url = {http://link.aps.org/doi/10.1103/PhysRevB.80.245119}, author = {B. Meredig and C. Wolverton} } @article {984, title = {Giant onsite electronic entropy enhances the performance of ceria for water splitting}, journal = {Nature Communications}, volume = {8}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, issn = {2041-1723}, doi = {10.1038/s41467-017-00381-2}, url = {http://www.nature.com/articles/s41467-017-00381-2}, author = {S. Shahab Naghavi and Antoine A. Emery and Heine A. Hansen and Fei Zhou and Vidvuds Ozolins and Chris Wolverton} } @article {970, title = {High temperature hydrogen production: Design of a 750kW demonstration plant for a two-step thermochemical cycle}, journal = {Solar Energy}, volume = {135}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {232-241}, issn = {0038092X}, doi = {10.1016/j.solener.2016.05.059}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0038092X16301773}, author = {J.-P. S{\"a}ck and S. Breuer and P. Cotelli and A. Houaijia and M. Lange and M. Wullenkord and C. Spenke and M. Roeb and Chr. Sattler} } @article {969, title = {High-throughput computational screening of perovskites for thermochemical water splitting applications}, journal = {Chemistry of Materials}, volume = {28}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {5621-5634}, abstract = {*The authors use high throughput DFT to screen all possible simple, binary ABO3 perovskite formulations for gas-splitting favorability. It is the first demonstration of DFT applied to STC materials in this manner and points to the potential future impacts of computational chemistry in this field.}, issn = {0897-4756, 1520-5002}, doi = {10.1021/acs.chemmater.6b01182}, url = {http://pubs.acs.org/doi/abs/10.1021/acs.chemmater.6b01182}, author = {Antoine A. Emery and James E. Saal and Scott Kirklin and Vinay I. Hegde and Chris Wolverton} } @article {850, title = {Kinetics and thermodynamics of H2O dissociation on reduced CeO2(111)}, journal = {The Journal of Physical Chemistry C}, volume = {118}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {27402-27414}, issn = {1932-7447, 1932-7455}, doi = {10.1021/jp508666c}, url = {http://pubs.acs.org/doi/abs/10.1021/jp508666c}, author = {Heine A. Hansen and Christopher Wolverton} } @article {934, title = {Lanthanum{\textendash}strontium{\textendash}manganese perovskites as redox materials for solar thermochemical splitting of H2O and CO2}, journal = {Energy \& Fuels}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {130304073847002}, issn = {0887-0624, 1520-5029}, doi = {10.1021/ef301923h}, url = {http://pubs.acs.org/doi/abs/10.1021/ef301923h}, author = {Jonathan R. Scheffe and David Weibel and Aldo Steinfeld} } @article {1022, title = {Long-time anodisation of titanium in sulphuric acid}, journal = {Surface and Coatings Technology}, volume = {202}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {1379-1384}, abstract = {The long-time behaviour of CP titanium in 1~M H2SO4 has been investigated. The authors revealed electrochemical behaviour during the long-time chrono-amperometric experiments. The ex-situ observations (EIS, ellipsometry, SEM and optical microscopy) brought out information concerning morphological changes of the surface as well as the change in the oxide thickness during the anodic oxidation process. From the obtained data, the authors developed a hypothesis describing the potentiostatic anodisation of titanium at voltages (up to 15~V) in 1~M H2SO4 with respect to time of anodisation.}, issn = {0257-8972}, doi = {10.1016/j.surfcoat.2007.06.027}, url = {http://www.sciencedirect.com/science/article/pii/S0257897207006676}, author = {D. Capek and M. -P. Gigandet and M. Masmoudi and M. Wery and O. Banakh} } @article {1010, title = {Low-Cost and Durable Bipolar Plates for Proton Exchange Membrane Electrolyzers}, journal = {Scientific Reports}, volume = {7}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {44035}, abstract = {Cost reduction and high efficiency are the mayor challenges for sustainable H2 production via proton exchange membrane (PEM) electrolysis. Titanium-based components such as bipolar plates (BPP) have the largest contribution to the capital cost. This work proposes the use of stainless steel BPPs coated with Nb and Ti by magnetron sputtering physical vapor deposition (PVD) and vacuum plasma spraying (VPS), respectively. The physical properties of the coatings are thoroughly characterized by scanning electron, atomic force microscopies (SEM, AFM); and X-ray diffraction, photoelectron spectroscopies (XRD, XPS). The Ti coating (50 μm) protects the stainless steel substrate against corrosion, while a 50-fold thinner layer of Nb decreases the contact resistance by almost one order of magnitude. The Nb/Ti-coated stainless steel bipolar BPPs endure the harsh environment of the anode for more than 1000 h of operation under nominal conditions, showing a potential use in PEM electrolyzers for large-scale H2 production from renewables.}, issn = {2045-2322}, doi = {10.1038/srep44035}, url = {https://www.nature.com/articles/srep44035}, author = {P. Lettenmeier and R. Wang and R. Abouatallah and B. Saruhan and O. Freitag and P. Gazdzicki and T. Morawietz and R. Hiesgen and A. S. Gago and K. A. Friedrich} } @article {792, title = {Magnetic and electrical properties of quadruple perovskites with 12 layer structures Ba4LnM3O12 (Ln=rare earths; M=Ru, Ir): The role of metal{\textendash}metal bonding in perovskite-related oxides}, journal = {Journal of Solid State Chemistry}, volume = {183}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {1962-1969}, issn = {00224596}, doi = {10.1016/j.jssc.2010.06.023}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0022459610002744}, author = {Yuki Shimoda and Yoshihiro Doi and Makoto Wakeshima and Yukio Hinatsu} } @article {1007, title = {Methods of photoelectrode characterization with high spatial and temporal resolution}, journal = {Energy \& Environmental Science}, volume = {8}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {2863-2885}, abstract = {Materials and photoelectrode architectures that are highly efficient, extremely stable, and made from low cost materials are required for commercially viable photoelectrochemical (PEC) water-splitting technology. A key challenge is the heterogeneous nature of real-world materials, which often possess spatial variation in their crystal structure, morphology, and/or composition at the nano-, micro-, or macro-scale. Different structures and compositions can have vastly different properties and can therefore strongly influence the overall performance of the photoelectrode through complex structure{\textendash}property relationships. A complete understanding of photoelectrode materials would also involve elucidation of processes such as carrier collection and electrochemical charge transfer that occur at very fast time scales. We present herein an overview of a broad suite of experimental and computational tools that can be used to define the structure{\textendash}property relationships of photoelectrode materials at small dimensions and on fast time scales. A major focus is on in situ scanning-probe measurement (SPM) techniques that possess the ability to measure differences in optical, electronic, catalytic, and physical properties with nano- or micro-scale spatial resolution. In situ ultrafast spectroscopic techniques, used to probe carrier dynamics involved with processes such as carrier generation, recombination, and interfacial charge transport, are also discussed. Complementing all of these experimental techniques are computational atomistic modeling tools, which can be invaluable for interpreting experimental results, aiding in materials discovery, and interrogating PEC processes at length and time scales not currently accessible by experiment. In addition to reviewing the basic capabilities of these experimental and computational techniques, we highlight key opportunities and limitations of applying these tools for the development of PEC materials.}, issn = {1754-5706}, doi = {10.1039/C5EE00835B}, url = {http://pubs.rsc.org/en/content/articlelanding/2015/ee/c5ee00835b}, author = {Daniel V. Esposito and Jason B. Baxter and Jimmy John and Nathan S. Lewis and Thomas P. Moffat and Tadashi Ogitsu and Glen D. O{\textquoteright}Neil and Tuan Anh Pham and A. Alec Talin and Jesus M. Velazquez and Brandon C. Wood} } @article {925, title = {Modification of CeO2 on the redox property of Fe2O3}, journal = {Materials Letters}, volume = {93}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {129-132}, issn = {0167577X}, doi = {10.1016/j.matlet.2012.09.039}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0167577X12013195}, author = {Kongzhai Li and Masaaki Haneda and Zhenhua Gu and Hua Wang and Masakuni Ozawa} } @article {756, title = {Rate Constants of Electrochemical Reactions in a Lithium-Sulfur Cell Determined by Operando X-ray Absorption Spectroscopy}, journal = {Journal of The Electrochemical Society}, volume = {165}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {A3487-A3495}, abstract = {The reduction of sulfur during discharge in a lithium-sulfur (Li-S) cell is known to occur in a series of reaction steps that involve lithium polysulfide intermediates. We present an operando study of the discharge of a solid-state Li-S cell using X-ray absorption spectroscopy (XAS). In theory, the average chain length of the polysulfides, xavg,cell, at a given depth of discharge is determined by the number of electrons delivered to the sulfur cathode. The dependence of xavg,cell measured by XAS on the depth of discharge is in excellent agreement with theoretical predictions. XAS is also used to track the formation of Li2S, the final discharge product, as a function of depth of discharge. The XAS measurements were used to estimate rate constants of a series of simple reactions commonly accepted in literature.}, issn = {0013-4651, 1945-7111}, doi = {10.1149/2.0981814jes}, url = {http://jes.ecsdl.org/content/165/14/A3487}, author = {Dunyang Rita Wang and Deep B. Shah and Jacqueline A. Maslyn and Whitney S. Loo and Kevin H. Wujcik and Erik J. Nelson and Matthew J. Latimer and Jun Feng and David Prendergast and Tod A. Pascal and Nitash P. Balsara} } @article {771, title = {Resonant soft x-ray powder diffraction study to determine the orbital ordering in A-site-ordered SmBaMn 2 O 6}, journal = {Physical Review B}, volume = {77}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, issn = {1098-0121, 1550-235X}, doi = {10.1103/PhysRevB.77.060402}, url = {https://link.aps.org/doi/10.1103/PhysRevB.77.060402}, author = {M. Garc{\'\i}a-Fern{\'a}ndez and U. Staub and Y. Bodenthin and S. M. Lawrence and A. M. Mulders and C. E. Buckley and S. Weyeneth and E. Pomjakushina and K. Conder} } @article {764, title = {Resonant x-ray diffraction study of the charge ordering in magnetite}, journal = {Journal of Physics: Condensed Matter}, volume = {17}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {7633-7642}, issn = {0953-8984, 1361-648X}, doi = {10.1088/0953-8984/17/48/015}, url = {http://stacks.iop.org/0953-8984/17/i=48/a=015?key=crossref.b73fefddce8ebe019873c56a6156c521}, author = {Richard J Goff and Jon P Wright and J Paul Attfield and Paolo G Radaelli} } @article {884, title = {Solar-thermal production of renewable hydrogen}, journal = {AIChE Journal}, volume = {55}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {286-293}, issn = {00011541, 15475905}, doi = {10.1002/aic.11810}, url = {http://doi.wiley.com/10.1002/aic.11810}, author = {Christopher Perkins and Alan W. Weimer} } @article {788, title = {Structural requirements of manganese oxides for methane oxidation: XAS spectroscopy and transition-state studies}, journal = {Applied Catalysis B: Environmental}, volume = {229}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {52-62}, issn = {09263373}, doi = {10.1016/j.apcatb.2018.02.007}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0926337318301115}, author = {Xiuyun Wang and Yi Liu and Yangyu Zhang and Tianhua Zhang and Huazhen Chang and Yongfan Zhang and Lilong Jiang} } @article {780, title = {Surface Defect Chemistry and Electronic Structure of Pr 0.1 Ce 0.9 O 2-δ Revealed in Operando}, journal = {Chemistry of Materials}, volume = {30}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {2600-2606}, issn = {0897-4756, 1520-5002}, doi = {10.1021/acs.chemmater.7b05129}, url = {http://pubs.acs.org/doi/10.1021/acs.chemmater.7b05129}, author = {Qiyang Lu and Gulin Vardar and Maximilian Jansen and Sean R. Bishop and Iradwikanari Waluyo and Harry L. Tuller and Bilge Yildiz} } @article {857, title = {System efficiency for two-step metal oxide solar thermochemical hydrogen production {\textendash} Part 2: Impact of gas heat recuperation and separation temperatures}, journal = {International Journal of Hydrogen Energy}, volume = {41}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {19881-19893}, issn = {03603199}, doi = {10.1016/j.ijhydene.2016.07.110}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0360319915303542}, author = {Brian D. Ehrhart and Christopher L. Muhich and Ibraheam Al-Shankiti and Alan W. Weimer} } @article {858, title = {System efficiency for two-step metal oxide solar thermochemical hydrogen production {\textendash} Part 3: Various methods for achieving low oxygen partial pressures in the reduction reaction}, journal = {International Journal of Hydrogen Energy}, volume = {41}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {19881-19893}, issn = {03603199}, doi = {10.1016/j.ijhydene.2016.07.106}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0360319915303542}, author = {Brian D. Ehrhart and Christopher L. Muhich and Ibraheam Al-Shankiti and Alan W. Weimer} } @article {962, title = {System efficiency for two-step metal oxide solar thermochemical hydrogen production {\textendash} Part 1: Thermodynamic model and impact of oxidation kinetics}, journal = {International Journal of Hydrogen Energy}, volume = {41}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {19881-19893}, issn = {03603199}, doi = {10.1016/j.ijhydene.2016.07.109}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0360319915303542}, author = {Brian D. Ehrhart and Christopher L. Muhich and Ibraheam Al-Shankiti and Alan W. Weimer} } @article {949, title = {Thermal Reduction of Ceria within an Aerosol Reactor for H 2 O and CO 2 Splitting}, journal = {Industrial \& Engineering Chemistry Research}, volume = {53}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {2175-2182}, issn = {0888-5885, 1520-5045}, doi = {10.1021/ie402620k}, url = {http://pubs.acs.org/doi/abs/10.1021/ie402620k}, author = {Jonathan R. Scheffe and Michael Welte and Aldo Steinfeld} } @article {802, title = {Thermodynamic modeling of the hybrid sulfur (HyS) cycle for hydrogen production}, journal = {Fluid Phase Equilibria}, volume = {460}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {175-188}, abstract = {We have developed a comprehensive thermodynamic model for the ternary system sulfur dioxide~+~sulfuric acid~+~water based on a previously published thermodynamic model of the aqueous sulfuric acid system using the symmetric electrolyte NRTL (eNRTL) activity coefficient model. The eNRTL binary interaction parameters and the chemical equilibrium constants are regressed from experimental SO2 solubility data in aqueous sulfuric acid solutions. The model accurately represents all thermodynamic properties including vapor-liquid equilibrium, liquid-liquid equilibrium, calorimetric properties, and speciation over a wide acid concentration range, from pure water to pure sulfuric acid and pure sulfur dioxide, and temperatures from 273.15 to 393.15 K. The model should be very useful in supporting process research, development, and design of advanced water-splitting processes based on the hybrid sulfur (HyS) cycle.}, issn = {0378-3812}, doi = {10.1016/j.fluid.2017.12.025}, url = {http://www.sciencedirect.com/science/article/pii/S0378381217305095}, author = {Harnoor Kaur and Meng Wang and Maximilian B. Gorensek and Chau-Chyun Chen} } @article {1031, title = {Understanding the Current-Voltage Behavior of High Temperature Solid Oxide Fuel Cell Stacks}, journal = {Journal of The Electrochemical Society}, volume = {164}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, pages = {F1460-F1470}, abstract = {High temperature solid oxide fuel cell (SOFC) stacks are highly efficient and environmentally friendly electrochemical systems, which convert the chemical energy of fuel gases with oxygen from air directly into electrical energy. During operation of SOFC stacks under system operating conditions pronounced temperature and fuel gas composition gradients along the cell area and along the height of the stack occur. Therefore, in contrast to SOFC cells, the electrochemical behavior of SOFC stacks is much more complex and has not sufficiently been studied. Specially, a shortcoming exists in terms of understanding the homogeneity, performance loss mechanisms, and various resistances and overvoltages within the stack repeat components. Therefore, this paper focuses on the improvement of the understanding and of the interpretation of different current-voltage curves of solid oxide fuel cell stack repeat units. Three different cases are discussed: repeat units with high power performance, with high cell contact resistance and with high fuel utilization. The stacks were investigated by current-voltage curves, electrochemical impedance spectroscopy and gas analysis. In order to understand the electrochemical behavior of these three cases both experimental and modeling results are presented, compared and discussed.}, issn = {0013-4651, 1945-7111}, doi = {10.1149/2.1541713jes}, url = {http://jes.ecsdl.org/content/164/13/F1460}, author = {M. Lang and C. Bohn and M. Henke and G. Schiller and C. Willich and F. Hauler} } @article {787, title = {Understanding the spectroscopic signatures of Mn valence changes in the valence energy loss spectra of Li-Mn-Ni-O spinel oxides}, journal = {Physical Review Materials}, volume = {1}, note = {{\textquoteright}doi: 10.1021/acsenergylett.0c01132\n - I.Am.Hydrogen{\textquoteright} {\textquoteright}\n - jyoungstrom{\textquoteright} {\textquoteright}Jason thinks this is great.\n~\n - jyoungstrom{\textquoteright} {\textquoteright}\n - estechel{\textquoteright} }, issn = {2475-9953}, doi = {10.1103/PhysRevMaterials.1.074402}, url = {https://link.aps.org/doi/10.1103/PhysRevMaterials.1.074402}, author = {M. K. Kinyanjui and P. Axmann and M. Mancini and G. Gabrielli and P. Balasubramanian and F. Boucher and M. Wohlfahrt-Mehrens and U. Kaiser} }