Dopant-Tuned Restructuring Kinetic for the Formation of Heterophase-Confined Metal-Nonmetal Diatomic Sites for Efficient Oxygen Evolution Reaction

Abstract

Engineering the electronic structure and microenvironments of active sites is an effective strategy to enhance the oxygen evolution reaction (OER) kinetics. Meanwhile, most OER materials act only as precatalysts; therefore, understanding and modulation of restructuring kinetics is crucial for developing efficient OER active sites. Herein, a dopant-tuned restructuring kinetic for the generation of heterophase-confined metal-nonmetal diatomic sites has been achieved. Both operando spectra and theoretical evidence show that Zr dopants tune in situ restructuring kinetics and induce charge transfer between Ni and Se to generate Ni–Se diatomic sites that coordinate dynamically with oxygenated intermediates and reduce energy barriers significantly. Consequently, the dense Ni–Se diatomic sites display an overpotential of 224 mV vs reversible hydrogen electrode at 10 mAcm^–2 and stable operation over 500 h in alkaline conditions, one of the best performances among reported selenide-derived OER catalysts. Our results enable an in-depth understanding of dynamically restructured diatomic sites beyond the conventional single-metal sites and expand the strategies for engineering atomic/molecular-level active sites.