Reducing the Barrier Energy of Self-Reconstruction for Anchored Cobalt Nanoparticles as Highly Active Oxygen Evolution Electrocatalyst.

Abstract

It is crucial for leaping forward renewable energy technology to develop highly active oxygen evolution reaction (OER) catalysts with fast OER kinetics, and the novel design of high-performance catalysts may come down to unveiling the origin of high catalytic behavior. Herein, a new class of heterogeneous OER electrocatalyst (metallic Co nanoparticles anchored on yttrium ruthenate pyrochlore oxide) is provided for securing fast OER kinetics. In situ X-ray absorption spectroscopy (in situ XAS) reveals that fast OER kinetics can be achieved by the harmonious catalytic synergy of a pyrochlore oxide support to Co nanoparticles. By the facile oxidation of yttrium (A-site) and ruthenium (B-site) cations, the pyrochlore oxide support helps to expel the electrons generated from the catalytic behavior of Co to the inner layers of the support, facilitating the electrostatic adsorption of OH^- ions and reducing the barrier energy for the formation of CoOOH intermediates. This work affords the rational design of transition metal nanoparticles anchored on pyrochlore oxide heterogeneous catalysts and the fundamental insight of catalytic origin associated with self-reconstruction of OER electrocatalysts.