Multistage orbital hybridization induced by multisite exchange interactions in high-entropy perovskites for high oxygen evolution reaction

The oxygen evolution reaction (OER) has garnered considerable attention because of its promising prospects in electrochemical energy conversion applications, but a significant challenge is faced by the insufficient understanding of sluggish OER kinetics. In fact, the intrinsic "acceptance-donation" process of electrons between active sites and reactants is responsible for improving OER activity. Herein, we suggest a multielement hybridization strategy to rematch spin electron occupation and energy splitting in high-entropy perovskites with multiple orbital coordination. In this concept, electronic hopping between t2g and eg orbitals among particular catalytic sites can be obviously enforced due to introducing more favorable energy levels from neighboring metal sites, which can demonstrate multistage orbital hybridization reaction activity. As a result, our proposed multistage-hybridized high-entropy perovskites display an impressive activity of 199.8 mA cm-2 as an overpotential of ∼0.46 V, which is ∼5.3 times that of pristine perovskite. Different from traditional catalyst designs, this study focuses on multistage orbital hybridization and electron exchange interactions through a multisite coordination mechanism to construct a fast reaction pathway. Our findings provide a new strategy for accelerating OER catalytic kinetics.