Electrocatalytic Water Oxidation Activity‐Stability Maps for Perovskite Oxides Containing 3d, 4d and 5d Transition Metals

Abstract Improving catalytic activity without loss of catalytic stability is one of the core goals in search of low‐iridium‐content oxygen evolution electrocatalysts under acidic conditions. Here, we synthesize a family of 66 SrBO 3 perovskite oxides (B=Ti, Ru, Ir) with different Ti : Ru : Ir atomic ratios and construct catalytic activity‐stability maps over composition variation. The maps classify the multicomponent perovskites into chemical groups with distinct catalytic activity and stability for acidic oxygen evolution reaction, and highlights a chemical region where high catalytic activity and stability are achieved simultaneously at a relatively low iridium level. By quantifying the extent of hybridization of mixed transition metal 3 d ‐4 d ‐5 d and oxygen 2 p orbitals for multicomponent perovskites, we demonstrate this complex interplay between 3 d ‐4 d ‐5 d metals and oxygen atoms in governing the trends in both activity and stability as well as in determining the catalytic mechanism involving lattice oxygen or not.