A molecular-level strategy to boost the mass transport of perovskite electrocatalyst for enhanced oxygen evolution

Perovskite oxides are of particular interest for the oxygen evolution reaction (OER) due to their high intrinsic activity. However, low surface area and nonpores in bulk phase generally limit mass transport thereby result unsatisfactory Herein, we propose a “molecular-level strategy” with simultaneous modulation ordered pores on oxygen-deficient sites along sulfur (S) substitution at molecular level boost behavior perovskite electrocatalyst enhanced As proof concept, elaborately designed brownmillerite oxide Sr2Co1.6Fe0.4O4.8S0.2 (S-BM-SCF) shows approximately fourfold activity enhancement 1 M KOH compared pristine SrCo0.8Fe0.2O3-δ (SCF) perovskite. Comprehensive experimental results, combination theoretical calculations, demonstrate that molecular-level structure can facilitate reactive hydroxyl ion (OH−) uptake into oxygen-vacant S doping further promotes OH− adsorption by electronic modulation, thus accelerating rate. Meanwhile, S-BM-SCF significantly weaken resistance O2 desorption catalyst surface, facilitating evolution. This work deepens understanding how impacts kinetics OER process opens up new avenue design high-performance catalysts level.