Building of Amorphous Cu _x O With Cu─O─Si Interface for CO ₂ Reduction to C <

ABSTRACT

Amorphous copper‐based catalysts with a large number of undercoordination sites exhibit promising catalytic performance for the electrocatalytic CO ₂ reduction reaction (eCO ₂ RR). However, their structure stability of amorphous Cu _x O is significant for achieving high‐efficiency catalytic performance and excellent stability. Herein, amorphous Cu _x O nanoparticles embedded uniformly in mesoporous silica spheres (Cu _x O@mSiO ₂ ) were fabricated via a modified Stöber method combined with in situ electrochemical pre‐reduction. Experimentally, the Cu─O─Si interface suppresses the over‐reduction of CuO to metallic Cu and modulates the electronic structure of Cu species. It can be demonstrated that the resulting amorphous Cu _x O switches the adsorption of ^* CHO and ^* OCCO intermediates from conventional Cu‐anchoring configurations to lattice oxygen‐anchoring counterparts, significantly weakening the thermodynamic restriction for post‐CO coupling toward C ₂₊ pathway. Ideally, the Cu _x O@mSiO ₂ ‐0.4 catalyst achieves a C ₂₊ Faradaic efficiency of 40.1% with a partial current density of −10.8 mA∙cm ⁻² at −1.7 V vs. RHE, which is two times greater than that of crystalline CuO‐derived Cu. Furthermore, Cu _x O@mSiO ₂ maintains stable catalytic activity and selectivity over 9 h of continuous eCO ₂ RR reaction.