Influence of Supporting Electrolyte on Hydroxide Exchange Membrane Water Electrolysis Performance: Catholyte

Alkaline or hydroxide exchange membrane water electrolysis (HEMWE) is a promising technology for green hydrogen production using platinum group metal-free catalysts and stainless steel, an advantage of alkaline (AWE), gas-impermeable membrane, parallel to proton (PEMWE). However, the HEMWE requires supporting electrolytes there minimal understanding their role on respective reactions. Without SELs, performance durability are worse than PEMWE systems. Herein, consistently feeding potassium anolyte, we systematically study effects catholyte SELs in HEMWEs including dry vs. wet operation, cation effects, anion cation/OH ratios cell potential stability. We report that (i) hydration cathode improves high current density operation by preventing dehydration (HEM), (ii) was no correlation between type potential, (iii) frequency resistance did not correlate with SEL conductivity, (iv) cathodic carbonate had significant negative effect performance, (v) increased ratio also caused potentials. Overall, this concludes solution desirable improve AEMWE performance.