High-performance SO2-depolarized electrolysis cell using advanced polymer electrolyte membranes

Electrode optimization for efficient hydrogen production using an SO2-depolarized electrolysis cell

“…8 While Pt kinetics are generally not influenced by the acid concentration, 6 the ohmic overpotential increases due to the loss of hydration in the membrane. 5 However, one important effect of acid accumulation at the catalyst layer is its influence on the thermodynamic potential of the SDE reaction. Inefficient acid removal results in an increase in the local acid concentration, which is reflected as an increase in the open circuit potential and thus an overall increase in cell potential.…”

“…9 Reversible cell potential, ohmic and kinetic overpotentials were calculated and measured according to published reports. 5 All overpotential calculations were performed assuming 100 % Faradaic efficiency for hydrogen and sulfuric acid production.…”

“…The current work focuses on improvements in the SDE process, as it is one of the major operations that impact the overall HyS cycle efficiency. Literaturereported results to date are far from the performance goals [4][5][6] (600 mV at 500 mA/cm 2 and 65 wt% sulfuric acid) set by technoeconomic analysis to meet the cost target. 7 From the literature, it is apparent that to meet the current, potential, and acid concentration goals simultaneously, operation must take place at high pressures and temperatures.…”

“…The procedures for measuring the cyclic voltammetry and cell break-in have been previously reported. 5 After break-in, the cell was held at 0.95 V and with a fixed SO2 flow (24 sccm; 1.4 stoichiometric ratio at 500 mA/cm 2 ). The cell was operated with 0.29 mL min -1 water fed to the cathode and without water fed to the anode.…”

“…Further details about the setup can be found in the Supporting Information and in previous work. 5 Optical Profilometry Optical profilometry of the two carbon substrates was obtained using the Keyence VR-3000 Wide Area 3D Measurement System. Images were taken at 160x magnification.…”