Reconstructed Copper Compound by Cerium Leaching for Enhanced Electrochemical CO ₂ ‐to‐Ethylene Conversion

Abstract Rationally modulating the reconstructed structure of electrocatalyst is an effective avenue toward selective electrochemical CO ₂ reduction (e‐CO ₂ RR). Herein, it is reported that a Ce‐incorporated Cu oxide (CeCuO _x ) can have prominent performance for the selective production of C ₂ H ₄ 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 CeCuO _x reconstructs to oxygen‐contained Cu with optimized Cu ⁰ /(Cu ⁺ +Cu ²⁺ ) 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 C _1–2 intermediates generation and activation are enhanced, achieving high C ₂ H ₄ selectivity and efficiency. Our work provides new insights into the relationship between the reconstructed structure and mechanism for boosting CO ₂ to multi‐carbon products.