Antireconstruction Cu Nanowire Catalysts Enabled by SiO2 Encapsulation for Durable Electrochemical CO2 Reduction

Structural reconstruction─an uncontrollable process that compromises the stability of Cu-based catalysts in electrochemical CO2 reduction (CO2R)─presents a major scientific challenge that has yet to be overcome. In this work, we develop a well-controlled SiO2 encapsulation approach to stabilize Cu-based CO2R electrocatalysts against reconstruction. Using Cu nanowires (CuNWs) as a model platform, we demonstrate that SiO2 encapsulation can significantly suppress Cu reconstruction while retaining ∼95% of the initial CO2R performance over 24-h stability tests at −1.15 V vs reversible hydrogen electrode (VRHE). In contrast, unencapsulated CuNWs exhibit severe structural deterioration with attenuated CO2R activity under identical testing conditions. In situ Raman studies and density functional theory (DFT) calculations reveal that the antireconstruction effect results from the formation of a robust Cu–O–Si interface that can not only serve as a structural anchor but also contribute to strengthening the Cu–Cu bonding at the exposed Cu active sites during CO2R operation. These results decipher the stabilizing mechanism of SiO2 encapsulation, and provide key insights for designing durable Cu-based CO2R electrocatalysts toward practical applications.