Boron-modified CuO as catalyst for electroreduction of CO2 towards C2+ products

The development for electroreduction of carbon dioxide (CO2) is crucial for achieving sustainable cycles and carbon neutrality. Electroreduction of CO2 to C2+ products can not only mitigate environmental issues by reducing CO2 but also provide high-value chemicals for modern industry. In this study, we synthesized CuO nanosheets (CuO NS) via simple hydrothermal method and modified its electron structure by in-situ boron (B) doping to produce B-CuO NS catalyst. The XPS spectra revealed the successfully doping of B into CuO NS, which obviously changes the electron density of Cu on the surface of CuO NS. As a result, B-CuO NS displayed a higher performance for electroreduction of CO2 compared with original CuO NS. The optimized B-CuO NS catalyst exhibits a faradaic efficiency of 54.78 % for C2+ production at −1.2 V vs. reversible hydrogen electrode (RHE). Based on the structural characterization and Density Functional Theory (DFT) calculations, the introduction of B increases the charge density of Cu, which could process free electrons to adsorb *CO. Thanks to the easier adsorbing of *CO on B-CuO NS as well as the lower adsorption energy of *CO on Cu, C–C coupling reaction was promoted to produce more C2+ products. This work shows a rational design strategy for developing efficient catalysts for electroreduction of CO2.