CeO2-modulated Cu-based heterointerface catalysts promotes selective CO2 electroreduction to ethanol

Electrochemical pre-reconstruction creates CuO/Cu 2 O/Cu/CeO 2 @C heterointerfaces. • Carbon confinement stabilizes multivalent Cu interfaces during CO 2 electroreduction. • CeO 2 modulates the electronic structure and interfacial charge distribution of Cu. • Reconstructed interfaces tune the thermodynamics of *CO and *OCCO formation. • Ethanol Faradaic and cathodic energy efficiencies reach 75.6% and 30.9% at −0.9 V vs. RHE. The electrochemical CO 2 reduction reaction (CO 2 RR) to ethanol provides a carbon–neutral route for the sustainable production of value-added chemicals, yet achieving high ethanol selectivity remains challenging. Herein, we report a Ce-containing Cu-based oxide precursor embedded in a carbon framework, which undergoes electrochemical pre-reconstruction to form CuO/Cu 2 O/Cu/CeO 2 @C heterostructure featuring active multi-heterointerfaces. By optimizing the Ce content, the reconstructed catalyst delivers a high ethanol Faradaic efficiency of 75.6% and an energy efficiency of 30.9% at −0.9 V versus the reversible hydrogen electrode in a flow-cell reactor, outperforming most reported Cu-based CO 2 RR electrocatalysts. Comprehensive structural characterizations reveal that the carbon confinement layer mitigates excessive reduction of Cu species and stabilizes the multivalent Cu interfacial environment during CO 2 RR, while CeO 2 modulates the local electronic structure and induces interfacial charge redistribution over Cu sites. In situ characterization combined with theoretical calculations further reveals that interfacial environment modifies the relative thermodynamics of *CO and *OCCO formation. This work provides profound insights into interfacial charge-redistribution-mediated ethanol selectivity and provides a design strategy for high-performance advanced Cu-based CO 2 RR electrocatalysts. Download: Download high-res image (80KB) Download: Download full-size image