Parametric study of operating conditions of an SO2-depolarized electrolyzer

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

“…It is known that the product acid concentration has an important effect on the electrochemical performance of SDE production of sulfuric acid and hydrogen. 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.…”

“…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. 8 However, the harsh chemistry of the SDE limits the range of system component materials that can withstand the target operating conditions. In this work, low-loading precious metal electrodes prepared using easy-to-scale roll-to-roll techniques on two different PTMs were evaluated in MEAs.…”

Enhancement of the Green H2 Production by Using TiO2 Composite Polybenzimidazole Membranes

“…Most works have employed Nafion membranes at temperatures lower than 80 °C, as it is an operational limit for these kind of membranes [ 14 , 15 , 16 ]. On the other hand, some works recommend the electrolysis to be above 100 °C for a better water management and to increase the overall thermal efficiency of the HyS cycle [ 17 , 18 , 19 ]. Nevertheless, there are only a few works that study the electrolysis step at high temperature.…”

Electrospray Deposition of Catalyst Layers with Ultralow Pt Loading for Cost-Effective H2 Production by SO2 Electrolysis

“… Several studies have been established to improve the performance and the efficiency of the SO 2 -depolarized electrolysis (SDE) by developing new SDE electrolyzer materials and optimizing the operating conditions. Gorensek et al 11 , 14 , 15 extensively studied the thermodynamic properties and the operating conditions of this system using Aspen Plus. They determined the effect of sulfuric acid concentration on SO 2 solubility and on the operating overpotential and discussed the interactions among the inlet flow rates, applied current, cell temperature, and pressure on the resulting cell voltage and acid concentration in the liquid product stream.…”

“…Recently, it was concluded that constant current densities of 0.5, 0.75, and 1 A/ cm 2 can be produced at cell voltages of 0.59, 0.63, and 0.67 V, respectively, with an acid concentration of 65 wt % H 2 SO 4 , using a sulfonated polybenzimidazole (s-PBI) membrane and a platinum catalyst and by maintaining a cell temperature of 130 °C, a pressure of 2 bar, and a water-to-SO 2 stoichiometry of 2.77. 15 It is important to take into account that these results are not experimental but simulations with ideal conditions. Kruger et al 16−18 investigated the pretreatment and stability of a PBI-based blended proton exchange membrane and the influence of membrane electrode assembly (MEA) manufacturing techniques such as hot-pressing on an SO 2 electrolyzer.…”