Optimizing the coordination environment of Cu single-atom catalyst for efficient electroreduction of CO2 to CH3OH

Abstract

The electrocatalytic reduction of CO2 to methanol driven by renewable energy sources emerges as a promising solution to address both energy crises and environmental concerns. In this study, we optimize the adjustable coordination environments of single-atom Cu catalysts to modulate the binding affinity of the key intermediate (*CO) with the Cu active site, which significantly enhances the Faradaic efficiency of CH3OH from 29% to 80%. partial current density of CH3OH over the CuN3-C catalyst is up to −331 mA cm−2 with production rate of 0.57 μmol s−1 cm−2 at −1.0 V (vs RHE), positioning its performance at the forefront of reported catalysts to date. In situ Raman spectroscopy and density functional theory (DFT) calculations elucidate that the CuN3-C catalyst effectively stabilizes the *CO intermediate. Theoretical calculations further indicate that *CHOH intermediate, adsorbed at the Cu catalytic site with unsaturated coordination, which is more favorable to form *CH2OH intermediate than *CHOH2 during the subsequent hydrogenation step. This phenomenon effectively redirects the reaction pathway towards methanol formation. This work offers novel insights into structural optimization for the design of efficient CO2-to-CH3OH electrocatalysts.