Reconstructed Copper Compound by Cerium Leaching for Enhanced Electrochemical CO2-to-Ethylene Conversion.

Rationally modulating the reconstructed structure of electrocatalyst is an effective avenue toward selective electrochemical CO2 reduction (e-CO2RR). Herein, it is reported that a Ce-incorporated Cu oxide (CeCuOx) can have prominent performance for the selective production of C2H4 with a high Faraday efficiency (FE) of 55.39% at -0.93 V, and partial current density of -39.50 mA cm-2 at -1.03 V, higher than those of Cu oxide and Cu at the same potential. Systematical experimental investigations show that the CeCuOx reconstructs to oxygen-contained Cu with optimized Cu0/(Cu++Cu2+) ratio and electronic structure through Ce leaching and in situ reduction. All of those benefit water molecule cleavage and OH- accumulation that could provide hydrogen feedstock and suppress competitive hydrogen evolution. Importantly, specific C1-2 intermediates generation and activation are enhanced, achieving high C2H4 selectivity and efficiency. Our work provides new insights into the relationship between the reconstructed structure and mechanism for boosting CO2 to multi-carbon products.