Perovskite Catalysts for Pure-Water-Fed Anion-Exchange-Membrane Electrolyzer Anodes: Co-Design of Electrically Conductive Nanoparticle Cores and Active Surfaces

Anion-exchange-membrane water electrolyzers (AEMWEs) are a possible low-capital expense, efficient, and scalable hydrogen-production technology with inexpensive hardware, earth-abundant catalysts, and pure-water. However, pure-water-fed AEMWEs are still at an early stage of development and suffer from inferior performance compared to proton-exchange-membrane water electrolyzers (PEMWEs). One key challenge is to develop effective non-platinum group metal (non-PGM) anode catalysts and electrodes in pure-water-fed AEMWEs. We show how LaNiO3-based perovskite oxides can be tuned by co-substitution on both A- and B-sites to simultaneously maintain high metallic electrical conductivity along with controlled surface reconstruction to expose stable Co-based active catalyst. The optimized perovskite, Sr0.1La0.9Co0.5Ni0.5O3, yielded pure-water AEMWEs operating at 1.97 V at 2 A cm–2 at 70 oC with pure-water feed, thus illustrating the utility of the catalyst design principles.