An IrRuOx catalyst supported by oxygen-vacant Ta oxide for the oxygen evolution reaction and proton exchange membrane water electrolysis

through more electron-rich Ir, indicating strong synergy between the catalyst and the support. The use of a metal oxide support improves the catalyst dispersion, optimizes electronic structures, facilitates mass transport, and stabilizes active sites. This work demonstrates that compositing Ir with less expensive Ru and anchoring catalyst nanoparticles on platinum-group metal (PGM)-free metal oxide supports represents one of the most promising strategies to reduce Ir loading and achieve an activity-stability trade-off. Such a strategy can benefit future catalyst design for other energy storage and conventional processes.