Positive Electronic Nickel Active Site Enhances N─H/C─H Bonds Breaking for Electrooxidation of Amines to Nitriles Coupling with Hydrogen Production

Abstract

AbstractElectrocatalytic conversion of amines to nitriles can be used as biomass upgrading to assist hydrogen production in water electrolysis. However, achieving efficient N─H/C─H bond breaking in amines oxidation remains a challenge. Herein, the nitrogen‐doped carbon supported NiO nanoparticles with positive electronic nickel active site are simply synthesized to achieve ∽99% selectivity and complete conversion in electrooxidizing amines to nitriles, and the onset potential of the whole reaction is as low as 1.32 V vs. RHE. Detailed in situ characterizations and theoretical calculations prove that the carbon substrate enhances the interaction between the N 2p orbital of amines and the Ni 3d orbital, which favors the construction of an indirect oxidation intermediate state R‐CH2NH2···NiO(OH)abs and  promotes the subsequent stepwise dehydrogenation to nitriles. This whole reaction produces 16.4 times more hydrogen than pure water splitting, facilitating the development of the chemicals industry and energy utilization.