Semimetallic Orbital Hybridization by Particular Surface Engineering in Ternary Cobalt Silicide to Accelerate Oxygen Evolution Reaction

Abstract

The oxygen evolution reaction (OER) plays an important role in efficient energy conversion, but needs excellent catalysts to overcome the sluggish reaction kinetics. The classic reaction kinetics implies that catalytic activity strongly depends on the electronic‐state occupation at surface active sites. Herein, a semimetallic orbital‐hybridization strategy is suggested to optimize the reaction activity of metal site at ternary cobalt silicide surface by particular interlayer electronic‐state coupling, which is completely different from the atomic configuration with double‐layered metal surface. The detailed analysis about electronic structure demonstrates that the semimetallic orbital hybridization is responsible for reducing OER activation barrier, due to a proper bonding strength. Instead, the stronger metallization cannot benefit a fast intermediate dissociation, which requires a higher activation barrier at OER. Herein, a new insight into accelerating OER by a particular surface engineering is provided.