Stabilizing Copper by a Reconstruction-Resistant Atomic Cu–O–Si Interface for Electrochemical CO₂ Reduction

Abstract

Copper (Cu), a promising catalyst for electrochemical CO₂ reduction (CO₂R) to multi-electron reduction products, suffers from an unavoidable and uncontrollable reconstruction process during the reaction, which not only may lead to catalyst deactivation but also brings great challenges to the exploration of the structure-performance relationship. Herein, we present an efficient strategy for stabilizing Cu with silica and synthesize reconstruction-resistant CuSiO_<i>x</i> amorphous nanotube catalysts with abundant atomic Cu-O-Si interfacial sites. The strong interfacial interaction between Cu and silica makes the Cu-O-Si interfacial sites ultrastable in the CO₂R reaction without any apparent reconstruction, thus exhibiting high CO₂-to-CH₄ selectivity (72.5%) and stability (FE_CH₄ remains above 60% after 12 h of test). A remarkable CO₂-to-CH₄ conversion rate of 0.22 μmol cm^-2 s^-1 was also achieved in a flow cell device. This work provides a very promising route for the design of highly active and stable Cu-based CO₂R catalysts.