P-d Orbital Hybridization Induced by p-Block Metal-Doped Cu Promotes the Formation of C2+ Products in Ampere-Level CO2 Electroreduction.

Abstract

Large-current electrolysis of CO2 to multi-carbon (C2+) products is critical to realize the industrial application of CO2 conversion. However, the poor binding strength of *CO intermediates on the catalyst surface induces multiple competing pathways, which hinder the C2+ production. Herein, we report that p-d orbital hybridization induced by Ga-doped Cu (CuGa) could promote efficient CO2 electrocatalysis to C2+ products at ampere-level current density. It was found that CuGa exhibited the highest C2+ productivity with a remarkable Faradaic efficiency (FE) of 81.5% at a current density of 0.9 A/cm2, and the potential at such a high current density was -1.07 V versus reversible hydrogen electrode. At 1.1 A/cm2, the catalyst still maintained a high C2+ productivity with an FE of 76.9%. Experimental and theoretical studies indicated that the excellent performance of CuGa results from the p-d hybridization of Cu and Ga, which not only enriches reactive sites but also enhances the binding strength of the *CO intermediate and facilitates C-C coupling. The p-d hybridization strategy can be extended to other p-block metal-doped Cu catalysts, such as CuAl and CuGe, to boost CO2 electroreduction for C2+ production. As far as we know, this is the first work to promote electrochemical CO2 reduction reaction to generate the C2+ product by p-d orbital hybridization interaction using a p-block metal-doped Cu catalyst.