@article {1132, title = {A Computational Framework to Accelerate the Discovery of Perovskites for Solar Thermochemical Hydrogen Production: Identification of Gd Perovskite Oxide Redox Mediators}, journal = {Advanced Functional Materials}, year = {2022}, pages = {2200201}, abstract = {A high-throughput computational framework to identify novel multinary perovskite redox mediators is presented, and this framework is applied to discover the Gd-containing perovskite oxide compositions Gd2BB'O6, GdA'B2O6, and GdA'BB'O6 that split water. The computational scheme uses a sequence of empirical approaches to evaluate the stabilities, electronic properties, and oxygen vacancy thermodynamics of these materials, including contributions to the enthalpies and entropies of reduction, ΔHTR and ΔSTR. This scheme uses the machine-learned descriptor τ to identify compositions that are likely stable as perovskites, the bond valence method to estimate the magnitude and phase of BO6 octahedral tilting and provide accurate initial estimates of perovskite geometries, and density functional theory including magnetic- and defect-sampling to predict STCH-relevant properties. Eighty-three promising STCH candidate perovskite oxides down-selected from 4392 Gd-containing compositions are reported, three of which are referred to experimental collaborators for characterization and exhibit STCH activity. The results demonstrate that the high-throughput computational scheme described herein{\textemdash}which is used to evaluate Gd-containing compositions but can be applied to any multinary perovskite oxide compositional space(s) of interest{\textemdash}accelerates the discovery of novel STCH active redox mediators with reasonable computational expense.}, keywords = {concentrated solar energy, density functional theory, hydrogen, Perovskite, thermochemical water splitting}, doi = {https://doi.org/10.1002/adfm.202200201}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202200201}, author = {Bare, Zachary J. L. and Morelock, Ryan J. and Musgrave, Charles B.} } @article {1140, title = {Formation of 6H-Ba3Ce0.75Mn2.25O9 During Thermochemical Reduction of 12R-Ba4CeMn3O12: Identification of a Polytype in the Ba(Ce,Mn)O3 Family}, journal = {Inorganic Chemistry}, volume = {61}, year = {2022}, month = {4}, keywords = {analytical chemistry, inorganic, layered perovskite, organic, oxide, physical, polytype, STCH, thermochemistry}, doi = {10.1021/acs.inorgchem.2c00282}, author = {Strange, Nicholas A. and Park, James Eujin and Goyal, Anuj and Bell, Robert T. and Trindell, Jamie A. and Sugar, Joshua D. and Stone, Kevin H. and Coker, Eric N. and Lany, Stephan and Shulda, Sarah and Ginley, David S.} } @article {1145, title = {Operational Limits of Redox Metal Oxides Performing Thermochemical Water Splitting}, journal = {Energy Technology}, volume = {10}, year = {2022}, pages = {2100222}, abstract = {Solar thermochemical hydrogen production is an attractive technology that stores intermittent solar energy in the form of chemical bonds. Efficient operation requires the identification of a redox-active metal oxide (MOx) material that can achieve high conversion of water to hydrogen at minimal energy input. Water splitting occurs by consecutive reduction and reoxidation reactions of MOx. MOx is reduced to MOx-δ and, in the second step, is reoxidized by water recovering the initial MOx and generate H2. The material must reduce at temperatures achievable in concentrated solar receiver/reactors, while maintaining a thermodynamic driving force to split water. At equilibrium, extent of reduction depends on temperature and oxygen partial pressure, and in this analysis, a set of thermodynamic properties, namely, enthalpy and entropy of oxygen vacancy formation, is sufficient to represent MOx. Herein, a method to easily classify materials based on these thermodynamic properties under any condition of oxygen partial pressure and temperature is presented. This method is based on fundamental thermodynamic principles and is applicable for any redox material with known thermodynamic properties. Despite the simplicity of the method, it is believed that this analysis will support future research in targeting thermodynamic properties of redox-active metal oxides.}, keywords = {Hydrogen production, solar energy, thermochemical cycles, thermodynamic properties, water splitting}, doi = {https://doi.org/10.1002/ente.202100222}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/ente.202100222}, author = {Bayon, Alicia and de la Calle, Alberto and Stechel, Ellen B. and Muhich, Christopher} } @article {1147, title = {Redox Defect Thermochemistry of FeAl2O4 Hercynite in Water Splitting from First-Principles Methods}, journal = {Chemistry of Materials}, volume = {34}, year = {2022}, pages = {519-528}, keywords = {concentrated solar, Hercynite, hydrogen lcroduction, Perovskite, Redox Defect, screening, thermochemistry, thermogravimetry, water splitting}, doi = {10.1021/acs.chemmater.1c01049}, url = {https://doi.org/10.1021/acs.chemmater.1c01049}, author = {Millican, Samantha L. and Clary, Jacob M. and Musgrave, Charles B. and Lany, Stephan} } @article {1150, title = {System and technoeconomic analysis of solar thermochemical hydrogen production}, journal = {Renewable Energy}, volume = {190}, year = {2022}, pages = {294-308}, abstract = {Hydrogen is a promising energy carrier that can be obtained from various feedstocks using renewable energy sources. Direct solar thermochemical hydrogen (STCH) production by water splitting can utilize the full spectrum of solar radiation and has the potential to achieve high solar energy conversion efficiencies. Currently STCH research areas focus on material discovery. This paper evaluates the performance of various STCH materials in the context of a system platform to assess techno-economic benefits and gaps in the path to STCH scale-up. To analyze the hydrogen production cost, a concentrating solar thermal (CST) system is introduced as a platform for integrating STCH materials and accommodating generalized thermochemical processes. The thermochemical process is based on a two-step STCH cycle using metal oxide that consists of a high temperature step for metal oxide reduction, followed by an oxidation step for water splitting at a lower temperature. A preferred configuration is to have the high temperature step occurring in a directly irradiated solar receiver reactor. To this end, we conceptualized a receiver design and associated solar field layout and investigated STCH operational boundaries, component costs and sensitivity parameters on the $2/kgH2 goal of hydrogen production. The study explored system-related variables and factors associated with scaling up. The CST platform allows more comprehensive studies that encompass aspects of STCH materials and systems such as cost, hydrogen productivity and replacement frequency, alongside other system components like heliostat field, tower, and potential receiver costs.}, keywords = {H2A analysis, Hydrogen production, Solar receiver, Solar thermochemical hydrogen production, Technoeconomic analysis, water splitting}, issn = {0960-1481}, doi = {https://doi.org/10.1016/j.renene.2022.03.108}, url = {https://www.sciencedirect.com/science/article/pii/S0960148122003925}, author = {Zhiwen Ma and Patrick Davenport and Genevieve Saur} } @article {1133, title = {A Thermogravimetric Temperature-Programmed Thermal Redox Protocol for Rapid Screening of Metal Oxides for Solar Thermochemical Hydrogen Production}, journal = {Frontiers in Energy Research}, volume = {10}, year = {2022}, month = {04}, pages = {856943}, keywords = {concentrated solar, hydrogen lcroduction, Perovskite, screening, thermogravimetry, water splitting}, doi = {10.3389/fenrg.2022.856943}, author = {Sanders, Michael and Bergeson-Keller, Anyka and Coker, Eric and O{\textquoteright}Hayre, Ryan} } @article {1159, title = {Layer-structured triple-conducting electrocatalyst for water-splitting in protonic ceramic electrolysis cells: Conductivities vs. activity}, journal = {Journal of Power Sources}, volume = {495}, year = {2021}, pages = {229764}, abstract = {Electron, proton and oxygen-triple-conducting materials are becoming the dominant steam electrode candidate to break the rate limit on the water-splitting reaction that throttles the performance of protonic ceramic electrolysis cells (PCECs). In this study, based on Pr2NiO4+δ Ruddlesden-Popper phase, we manipulate these conductivities by Pr-site Ba substitution to probe the correlation of each conductivity with the kinetics of the elementary reaction steps. It is found that the proton conductivity is vital to sustain an extended active surface area for faster adsorption of reactants and desorption of products. The effect of oxygen conductivity is surprisingly found insignificant in the water-splitting reaction. On the contrary, surface oxygen removal is discovered as the most rate-limiting process. The electronic conductivity is not a direct limiting factor. However, an electron transfer process between the current collector and the electrode junction could introduce extra resistance that is perceptible at a high operating temperature range. The best water-splitting activity is obtained on a proton conductivity/oxygen surface desorption capability well-balanced sample after Ba substitution. As a result, a water-splitting reaction resistance of 0.022 Ωcm2, a current density of 1.96 A/cm2 at 700~{\textdegree}C is achieved on Pr1.7Ba0.3NiO4+δ, one of the best performances for PCECs.}, keywords = {Hydrogen generation, Protonic ceramic electrolysis cells, Ruddlesden-popper phase, Triple-conducting electrocatalyst, Water-splitting}, issn = {0378-7753}, doi = {https://doi.org/10.1016/j.jpowsour.2021.229764}, url = {https://www.sciencedirect.com/science/article/pii/S0378775321003050}, author = {Wenyuan Li and Bo Guan and Tao Yang and Zhongqiu Li and Wangying Shi and Hanchen Tian and Liang Ma and Thomas L. Kalapos and Xingbo Liu} } @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 {1162, title = {Performance Indicators for Benchmarking Solar Thermochemical Fuel Processes and Reactors}, journal = {Frontiers in Energy Research}, volume = {9}, year = {2021}, abstract = {Concentrated solar energy offers a source for renewable high-temperature process heat that can be used to efficiently drive endothermic chemical processes, converting the entire spectrum of solar radiation into chemical energy. In particular, solar-driven thermochemical processes for the production of fuels include reforming of methane and other hydrocarbons, gasification of biomass, coal, and other carbonaceous feedstock, and metal oxide redox cycles for splitting H2O and CO2. A notable issue in the development of these processes and their associated solar reactors is the lack of consistent reporting methods for experimental demonstrations and modelling studies, which complicates the benchmarking of the corresponding technologies. In this work we formulate dimensionless performance indicators based on mass and energy balances of such reacting systems, namely: energy efficiency, conversion extent, selectivity, and yield. Examples are outlined for the generic processes mention above. We then provide guidelines for reporting on such processes and reactors and suggest performance benchmarking on four key criteria: energy efficiency, conversion extent, product selectivity, and performance stability.}, keywords = {benchmarking, concentrated solar power, solar fuels and chemicals, solar reactors, thermochemical processes}, issn = {2296-598X}, doi = {10.3389/fenrg.2021.677980}, url = {https://www.frontiersin.org/article/10.3389/fenrg.2021.677980}, author = {Bulfin, Brendan and Miranda, Miguel and Steinfeld, Aldo} } @article {1121, title = {Techno-Economic Analysis of Thermochemical Water-Splitting System for Co-Production of Hydrogen and Electricity}, journal = {International Journal of Hydrogen Energy}, volume = {46}, year = {2021}, pages = {1656-1670}, keywords = {Techno-economic analysis}, doi = {https://doi.org/10.1016/j.ijhydene.2020.10.060}, author = {V. K. Budama and N. G. Johnson and I. Ermanoski and E. B. Stechel} } @article {1177, title = {Thin film growth effects on electrical conductivity in entropy stabilized oxides}, journal = {Journal of the European Ceramic Society}, volume = {41}, year = {2021}, pages = {2617-2624}, abstract = {Entropy stabilization has garnered significant attention as a new approach to designing novel materials. Much of the work in this area has focused on bulk ceramic processing, leaving entropy-stabilized thin films relatively under-explored. Following an extensive multi-variable investigation of polycrystalline (Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)O thin films deposited via pulsed laser deposition (PLD), it is shown here that substrate temperature and deposition pressure have strong and repeatable effects on film texture and lattice parameter. Further analysis shows that films deposited at lower temperatures and under lower oxygen chamber pressure are \~{}40{\texttimes} less electrically resistive than otherwise identical films grown at higher temperature and pressure. Annealing these films in an oxygen-rich environment increases their electrical resistivity to match that of the films grown at higher temperatures and pressures. Because of this, the electric conductivity is hypothesized to be the result of polaron hopping mediated by transition metal valence changes which compensate for oxygen off-stoichiometry.}, keywords = {electrical conductivity, Entropy, oxide, Phase, Polycrystalline oxide thin films, Pulsed laser deposition, STCH, Thin film}, issn = {0955-2219}, doi = {https://doi.org/10.1016/j.jeurceramsoc.2020.12.021}, url = {https://www.sciencedirect.com/science/article/pii/S0955221920309900}, author = {V. Jacobson and D. Diercks and B. To and A. Zakutayev and G. Brennecka} } @article {1168, title = {Deconvolution of Water-Splitting on the Triple-Conducting Ruddlesden{\textendash}Popper-Phase Anode for Protonic Ceramic Electrolysis Cells}, journal = {ACS Applied Materials \& Interfaces}, volume = {12}, year = {2020}, note = {PMID: 33079527}, pages = {49574-49585}, keywords = {atomic layer, proton conductors, relaxation time distribution, ruddlesden-popper phase, steam electrolysis, triple-conducting}, doi = {10.1021/acsami.0c12987}, url = {https://doi.org/10.1021/acsami.0c12987}, author = {Tian, Hanchen and Li, Wenyuan and Ma, Liang and Yang, Tao and Guan, Bo and Shi, Wangying and Kalapos, Thomas L. and Liu, Xingbo} } @article {1125, title = {Exploring Ca{\textendash}Ce{\textendash}M{\textendash}O (M = 3d Transition Metal) Oxide Perovskites for Solar Thermochemical Applications}, journal = {Chemistry of Materials}, volume = {32}, year = {2020}, pages = {9964-9982}, keywords = {Perovskites, Theory-driven materials discovery}, doi = {https://doi.org/10.1021/acs.chemmater.0c02912}, author = {G. Sai Gautam and E. B. Stechel and E. A. Carter} } @article {1129, title = {A First-Principles-Based Sub-Lattice Formalism for Predicting Off-Stoichiometry in Materials for Solar Thermochemical Applications: The Example of Ceria}, journal = {Advanced Theory and Simulations}, volume = {3}, year = {2020}, keywords = {off-stoichiometric materials, sub-lattice models, thermodynamic modeling}, doi = {https://doi.org/10.1002/adts.202000112}, author = {G. Sai Gautam and E. B. Stechel and E. A. Carter} } @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 {1167, title = {Triple ionic{\textendash}electronic conducting oxides for next-generation electrochemical devices}, journal = {Nature Materials}, volume = {20}, year = {2020}, month = {12/2020}, keywords = {electrolysis cells, fuel cells, ionic species transport, membrane reactors, Triple ionic{\textendash}electronic conductors}, issn = {1476-1122}, doi = {10.1038/s41563-020-00854-8}, url = {https://www.osti.gov/biblio/1762454}, author = {Papac, Meagan and Stevanovi{\'c}, Vladan and Zakutayev, Andriy and O{\textquoteright}Hayre, Ryan} } @article {1178, title = {Tungsten oxide-coated copper gallium selenide sustains long-term solar hydrogen evolution}, journal = {Sustainable Energy \& Fuels}, volume = {5}, year = {2020}, month = {12}, keywords = {CuGaSe, durability, PEC, Photocathode, Pt hydrogen evolution catalyst, Tungsten oxide protective coating}, doi = {10.1039/d0se00487a}, author = {Palm, David W. and Muzzillo, Christopher P. and Ben-Naim, Micha and Khan, Imran and Gaillard, Nicolas and Jaramillo, Thomas F.} } @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.} }