CuNi bimetallic nanocatalyst enables sustainable direct carboxylation reactions

Abstract

Herein, we combine catalyst synthesis, characterization, catalytic experiments, and theory to investigate the bimetallic CuNi-11 nanocatalyst for direct carboxylation of arenes. Catalytic experiments reveal that the CuNi-11 shows an excellent yield and a higher benzene conversion compared to monometallic Cu and Ni nanocatalysts. The bimetallic CuNi-11 nanocatalyst exhibits a high surface area of 58.993 m2/g with excellent reusability (up to 6 cycles) and the carboxylation reaction is an activator-, additive- and solvent-free taking place under mild conditions. Catalytic experiments are complemented by Density Functional Theory (DFT) calculations demonstrating a plausible mechanistic pathway involving C-H bond activation of benzene and formic acid. The benzoic acid and H2 formation with the benzene C–H activation being the rate-determining step. Overall, our work contributes to introducing sustainable and environmentally friendly carboxylation routes of arenes with a new mechanistic approach. © 2022