Cost-Effective Bimetallic Catalysts for Green H2 Production in Anion Exchange Membrane Water Electrolyzers

Green hydrogen production from water electrolysis (WE) is one of the most promising technologies to realize a decarbonized future and efficiently utilize intermittent renewable energy. Among the various WE technologies, the emerging anion exchange membrane (AEMWE) technology shows the greatest potential for producing green hydrogen at a competitive price. To achieve this goal, simple methods for the large-scale synthesis of efficient and low-cost electrocatalysts are needed. This paper deals with the synthesis of nanostructured NiCo- and NiFe-oxides and their evaluation as electrode materials in a zero-gap AEMWE full cell. Oxides with different Ni contents are synthesized by the sol-gel method, followed by calcination in air at different temperatures. The anode and cathode of the cell are fabricated using the as-prepared oxides and H2-/Ar-reduced oxides, respectively. Electrochemical testing of the synthesized catalysts reveals that phase purity and average crystal size significantly influence cell performance. Highly-pure and finely-grained electrocatalysts yield higher current densities at lower overpotentials. These findings underscore the critical role of catalyst composition and morphology in enhancing AEMWE efficiency, paving the way for scalable and cost-effective hydrogen production.