CuNi Aerogels with Suppressed Water Activation for Efficient Nucleophilic Methanol Electrooxidation

Abstract

Suppressing the competitive oxygen evolution reaction (OER) is the critical prerequisite for efficient nucleophile oxidation in electrochemical biomass upgrading coupled with hydrogen production. Herein, Cu 91 Ni 9 aerogels with atomically dispersed Ni are designed as effective nucleophile electrooxidation catalysts with significantly suppressed water activation performance, exhibiting a remarkable 99.3% Faradaic efficiency in the conversion of methanol to formic acid. Experimental and theoretical investigations reveal that the Cu support promotes the formation of Ni–O–Cu active pockets, where Ni 3+ behaves as the main adsorbed sites and electrophilic lattice oxygen in Ni–O–Cu serves as a hydrogen acceptor, thus accelerating the electrochemical catalyst dehydrogenation reaction and the spontaneous nucleophilic dehydrogenation reaction. Furthermore, Cu integration exhibits weaker OER competition by inactivating the deprotonation capacity of OH* to O*, promoting the Faradaic efficiency of formic acid. This work paves the way for the development of advanced catalysts to achieve highly efficient biomass upgrading by modulating the OER activity.