Enhanced Hydroxyl Adsorption in Ultrathin NiO/Cr2O3 In‐Plane Heterostructures for Efficient Alkaline Methanol Oxidation Reaction

Abstract

AbstractThe exploration of advanced nickel‐based electrocatalysts for alkaline methanol oxidation reaction (MOR) holds immense promise for value‐added organic products coupled with hydrogen production, but still remain challenging. Herein, we construct ultrathin NiO/Cr2O3 in‐plane heterostructures to promote the alkaline MOR process. Experimental and theoretical studies reveal that NiO/Cr2O3 in‐plane heterostructures enable a favorable upshift of the d‐band center and enhanced adsorption of hydroxyl species, leading to accelerated generation of active NiO(OH)ads species. Furthermore, ultrathin in‐plane heterostructures endow the catalyst with good charge transfer ability and adsorption behavior of methanol molecules onto catalytic sites, contributing to the improvement of alkaline MOR kinetics. As a result, ultrathin NiO/Cr2O3 in‐plane heterostructures exhibit a remarkable MOR activity with a high current density of 221 mA cm−2 at 0.6 V vs Ag/AgCl, which is 7.1‐fold larger than that of pure NiO nanosheets and comparable with other highly active catalysts reported so far. This work provides an effectual strategy to optimize the activity of nickel‐based catalysts and highlights the dominate efficacy of ultrathin in‐plane heterostructures in alkaline MOR.