Dual-site synergy boosting CO2 reduction to multi-carbon products on copper-conjugated electrocatalysts

Abstract

The electrochemical reduction of CO₂ offers a sustainable route to value-added chemicals and fuels. However, achieving high selectivity toward multi-carbon products remains challenging due to the kinetic barrier of C–C coupling and the competing hydrogen evolution reaction (HER). In this study, a conjugated porous organic electrocatalyst (Cu₃L₃–MPor, M = Cu, Ni) was constructed by integrating trinuclear copper clusters (Cu₃L₃) with porphyrin ligands through Schiff-base linkages. This framework provides dual catalytic centers: the Cu₃L₃ cluster promotes C–C coupling, while the porphyrin metal center acts as an additional active site and regulates charge redistribution. This dual-site configuration enables synergistic catalysis, with Cu₃L₃–CuPor achieving 87.5% total carbon products selectivity, including 56.7% toward C₂₊ products, outperforming the control catalysts. Density functional theory calculations further reveal that the porphyrin metal center regulates charge redistribution, thereby modulating the electron distribution at the Cu₃L₃ cluster and controlling product distribution.