Dual-site cation engineering of perovskite oxides for enhanced oxygen evolution electrocatalysis
Kaitao Li, Shimin Lai, Xintong Lv, Feifei Dong, Yufei Ma, Zhan Lin
Abstract
Perovskite oxides have emerged as promising electrocatalysts for the oxygen evolution reaction (OER) in water electrolysis, owing to their structural tunability and abundant redox-active sites. In particular, transition-metal-based perovskite oxides exhibit favorable intrinsic OER activity; however, their catalytic efficiency and operational stability still require further improvement to meet practical application demands. To address these challenges, we design a strategically modulated perovskite, Sm 0.1 SrCo 0.45 Fe 0.45 Ni 0.05 O 3-δ (SSCFN), featuring A-site enrichment and partial B-site substitution to enhance overall electrocatalytic performance and structural robustness. The co-introduction of excess Sm cations at the A-site and Ni cations at the B-site preserves lattice integrity and stabilizes a well-defined cubic phase, enabling synergistic modulation of key perovskite properties. Benefiting from increased oxygen vacancy concentration and improved electronic conductivity relative to the parent oxide SrCo 0.5 Fe 0.5 O 3-δ (SCF), SSCFN demonstrates outstanding OER performance, achieving a low overpotential of 319 mV at 10 mA cm −2 , a small Tafel slope of 73.5 mV dec −1 , and remarkable operational durability over 3000 min in alkaline media, specifically in 0.1 M KOH. These findings underscore the effectiveness of the synergistic A-site enrichment and multi-cation engineering strategy for developing high-performance perovskite OER catalysts with enhanced activity and durability.