Nano and phase engineering of Fe-Cu alloy exsolved perovskite oxide-based hetero-catalysts for efficient oxygen evolution reaction

Abstract

The electrochemical oxygen evolution reaction (OER), a crucial reaction in water electrolyzers and rechargeable metal–air batteries, requires for active electrocatalysts. Perovskite oxides possessing flexible composition and adjustable crystal structure and high intrinsic catalytic activity are potential candidates. However, distinct issues like low electrical conductivity and limited active sites hinder their wide application. To address these issues, we propose an integrated strategy that combines nanoarchitecture synthesis, nanoparticle exsolution design, and hybrid phase assembly with multi-interfacial interaction to create a phase controllable Fe/Cu nanoparticles-Ruddlesden-Popper structural-simple perovskite composites. Our results indicate that the composite catalyst LSFCN-R600 that was finally treated in 10% H2/N2 at 600 °C for 10 h with optimal metal phase exsolution and maximum surface/interfacial oxygen defects displayed the best OER activity: η10 = 381 mV and the Tafel slope 120 mV dec−1 as well as reliable performance in 20 h potentiostat test. The nano and heterostructural phase design increases the charge transfer rate and electrochemically active area. Our approach provides a reliable method for fabricating highly efficient perovskite oxide-based electrocatalysts that can be applied to various reactions and energy technologies.