Realizing high and stable electrocatalytic oxygen evolution for iron-based perovskites by co-doping-induced structural and electronic modulation

Abstract

Oxygen evolution reaction (OER) is a vital electrochemical process for various energy conversion and fuel production technologies. Co/Ni-rich perovskite oxides are extensively studied as promising alternatives to precious-metal catalysts; however, low-cost and earth-abundant iron (Fe)-rich perovskites are rarely investigated to date due to their poor activity and durability. This study reports an Fe-rich Sr0.95Ce0.05Fe0.9Ni0.1O3−δ (SCFN) perovskite oxide with minor Ce/Ni co-doping in A/B sites as a high-performance OER electrocatalyst. Impressively, SCFN shows more than an order of magnitude enhancement in mass-specific activity compared to the SrFeO3−δ (SF) parent oxide, and delivers an attractive small overpotential of 340 mV at 10 mA cm−2, outperforming many Co/Ni-rich perovskite oxides ever reported. Additionally, SCFN displays robust operational durability with negligible activity loss under alkaline OER conditions. The increased activity and stability of SCFN can be ascribed to co-doping-induced synergistic promotion between structural and electronic modulation, where Ce doping facilitates the formation of a 3D corner-sharing cubic structure and Ni doping gives rise to strong electronic interactions between active sites, which is key to achieving a highly active long-life catalyst. Importantly, this strategy is universal and can be extended to other Fe-based parent perovskite oxides with high structural diversity.