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

Boron-doped CuO nanosheets were obtained through one-step hydrothermal method and were investigated as catalyst for electroreduction of CO2. The optimized B1-CuO NS-2 demonstrates the highest FEEthylene of 38.56%, jEthylene of 11.78 mA cm−2 and FEC2+ of 54.78% at −1.2 V vs. RHE. The DFT calculation demonstrates that the incorporation of boron can increase the charge density and decrease the adsorption energy of CO, which facilitated electron transport and enhanced the selectivity of the catalyst towards the production of C2+ products. [Display omitted] •Preparation of boron-doped CuO nanosheets using a simple one-step hydrothermal method.•The doped boron changed charge density of Cu, leading to a decreased adsorption energy of *CO on Cu.•The doped boron enhanced the binding energy between Cu and *CO, facilitated electron transport, and promoted the production of C2+ products.•The faradic Efficiency of electroreduction of CO2 towards C2+ products reach to 54.78 %. 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.