Bidirectional Electronic Modulation within Cu2O Lattice for Ampere-Level CO2 Electroreduction to Ethylene.

Abstract

Electrochemical CO2 reduction to ethylene requires Cu sites that simultaneously enrich carbon intermediates, promote C-C coupling, and suppress hydrogen evolution at high current density. Heteroatom doping is widely used to tune Cu-based catalysts. However, conventional single-dopant strategies typically impose either electron donation or electron withdrawal, limiting their ability to balance these coupled interfacial processes. Herein, a Y single-atom and Cl co-modified Cu2O catalyst (Y0.19-Cu2O-Cl) is developed to create lattice-confined donor-acceptor pairs for bidirectionally modulating Cu electronic states. Formation energy calculations prove the favorable thermodynamics of Y-Cl co-doping configuration. HAADF-STEM, XPS, and XAS support atomically dispersed Y, retained Cl-containing species, and coupled charge redistribution within the Cu2O-derived matrix. In situ Raman/ATR-SEIRAS and density functional theory calculations reveal that Y favors *CO enrichment, whereas Cl modifies hydrogen adsorption; the two dopants synergistically regulate Cu+ active sites and lower the C-C coupling energy barrier from 0.75 to 0.39 eV. Consequently, the catalyst achieves an FEC2H4 of 62.5% at 656.6 mA cm-2 and maintains higher ethylene selectivity than the singly modified controls, establishing donor-acceptor electronic pairing as a strategy for industrial-grade current densities for CO2 electroreduction.