@article {1139,
	title = {Electrode optimization for efficient hydrogen production using an SO2-depolarized electrolysis cell},
	journal = {International Journal of Hydrogen Energy},
	volume = {47},
	year = {2022},
	pages = {14180-14185},
	abstract = {The hybrid sulfur (HyS) cycle offers an alternative route to hydrogen and sulfuric acid production using the SO2-depolarized electrolysis (SDE) cell. This work reports the most efficient SDE operation to date at high sulfuric acid concentrations (\~{}60~wt\%) achieved through the optimization of operating conditions and cell components. We observed that open porosity in the porous transport media (PTM) plays a significant role in SDE performance as it enables efficient acid removal from the catalyst layer. The combination of membrane electrode assembly (MEA) components, such as Sulfonated Diels Alder Poly (phenylene) (SDAPP) membranes and electrodes prepared using SGL 29BC PTM, and operating conditions (103.4 kPagauge at 125~{\textdegree}C) yielded electrolysis potentials <700~mV at 500~mA/cm2 and acid concentrations >60~wt\%.},
	keywords = {Catalysis, electrolysis, High pressure, Hybrid sulfur cycle, Hydrogen generation, Sulfur dioxide},
	issn = {0360-3199},
	doi = {https://doi.org/10.1016/j.ijhydene.2022.02.166},
	url = {https://www.sciencedirect.com/science/article/pii/S0360319922007807},
	author = {H{\'e}ctor R. Col{\'o}n-Mercado and Scott A. Mauger and Maximilian B. Gorensek and Cy H. Fujimoto and Aaron A. Lando and Prabhu Ganesan and Benjamin H. Meekins and Noah D. Meeks}
}
@article {1141,
	title = {High-performance SO2-depolarized electrolysis cell using advanced polymer electrolyte membranes},
	journal = {International Journal of Hydrogen Energy},
	volume = {47},
	year = {2022},
	pages = {57-68},
	abstract = {Three different proton conducting polymeric membrane materials (Nafion{\textregistered} 115, Nafion{\textregistered} 212, and sulfonated Diels-Alder polyphenylene [SDAPP]) were evaluated for use in SO2-depolarized electrolyzers for the production of hydrogen via the hybrid sulfur cycle. Their performance was measured using different water feed strategies to minimize overpotential losses while maintaining high product acid concentration. Both thin membranes (Nafion{\textregistered} 212 and SDAPP) showed performance superior to that of the thicker Nafion{\textregistered} 115. The SDAPP membrane electrode assembly (MEA) performed well at higher acid concentrations, maintaining low ohmic and kinetic overpotentials. Finally, short-term (100-h) stability tests under constant current conditions showed minimal degradation for the SDAPP and Nafion{\textregistered} 212 MEAs. SDAPP MEA performance approached the targets needed to make the hybrid sulfur cycle a competitive process for hydrogen production (product acid concentration >=65~wt\% H2SO4 at~<=~0.6-V cell potential and >=0.5 A-cm-2 current density).},
	keywords = {Hybrid sulfur (HyS) process, Hydrogen production, Sulfonated diels-alder polyphenylene (SDAPP), Sulfur dioxide-depolarized electrolyzer (SDE), Sulfuric acid production},
	issn = {0360-3199},
	doi = {https://doi.org/10.1016/j.ijhydene.2021.10.019},
	url = {https://www.sciencedirect.com/science/article/pii/S0360319921039343},
	author = {H{\'e}ctor R. Col{\'o}n-Mercado and Maximilian B. Gorensek and Cy H. Fujimoto and Aaron A. Lando and Benjamin H. Meekins}
}
@article {996,
	title = {Catalyst evaluation for a sulfur dioxide-depolarized electrolyzer},
	journal = {Electrochemistry Communications},
	volume = {9},
	year = {2007},
	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 = {2649-2653},
	abstract = {Published on November 1st, 2007.
Thermochemical processes are being developed to provide global-scale quantities of hydrogen. A variant on sulfur-based thermochemical cycles is the hybrid sulfur (HyS) process which uses a sulfur dioxide-depolarized electrolyzer (SDE) to produce the hydrogen. Testing examined the activity and stability of platinum and palladium as the electrocatalyst for the SDE in highly concentrated sulfuric acid solutions. Cyclic and linear sweep voltammetry revealed that platinum provided better catalytic activity with much lower potentials and higher currents than palladium. Testing also showed that the catalyst activity is strongly influenced by the concentration of the sulfuric acid electrolyte.},
	issn = {1388-2481},
	doi = {10.1016/j.elecom.2007.08.015},
	url = {http://www.sciencedirect.com/science/article/pii/S1388248107003451},
	author = {H{\'e}ctor R. Col{\'o}n-Mercado and David T. Hobbs}
}
@article {998,
	title = {Development and testing of a PEM SO2-depolarized electrolyzer and an operating method that prevents sulfur accumulation},
	journal = {International Journal of Hydrogen Energy},
	volume = {40},
	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 = {13281-13294},
	abstract = {The hybrid sulfur (HyS) cycle is being developed as a technology to generate hydrogen by splitting water, using heat and electrical power from a nuclear or solar power plant. A key component is the SO2-depolarized electrolysis (SDE) cell, which reacts SO2 and water to form hydrogen and sulfuric acid. SDE could also be used in once-through operation to consume SO2 and generate hydrogen and sulfuric acid for sale. A proton exchange membrane (PEM) SDE cell based on a PEM fuel cell design was fabricated and tested. Measured cell potential as a function of anolyte pressure and flow rate, sulfuric acid concentration, and cell temperature are presented for this cell. Sulfur accumulation was observed inside the cell, which could have been a serious impediment to further development. A method to prevent sulfur formation was subsequently developed. This was made possible by a testing facility that allowed unattended operation for extended periods.},
	issn = {0360-3199},
	doi = {10.1016/j.ijhydene.2015.08.041},
	url = {http://www.sciencedirect.com/science/article/pii/S0360319915021370},
	author = {John L. Steimke and Timothy J. Steeper and H{\'e}ctor R. Col{\'o}n-Mercado and Maximilian B. Gorensek}
}
