Construction of coherent interface between Cu2O and CeO2 via electrochemical reconstruction for efficient carbon dioxide reduction to methane

Developing an efficient electrocatalyst that enables the efficient electrochemical conversion from CO 2 to CH 4 across a wide potential range remains a formidable challenge. Herein, we introduce a precatalyst strategy that realizes the in situ electrochemical reconstruction of ultrafine Cu 2 O nanodomains, intricately coupled on the CeO 2 surface (Cu 2 O/CeO 2 ), originating from the heterointerface comprised of ultrafine CuO nanodomains on the CeO 2 surface (CuO/CeO 2 ). When served as the electrocatalyst for the electrochemical CO 2 reduction reaction, Cu 2 O/CeO 2 delivers a selectivity higher than 49 % towards CH 4 over a broad potential range from −1.2 V to −1.7 V vs . RHE, maintaining negligible activity decay for 20 h. Notably, the highest selectivity for CH 4 reaches an impressive 70 % at −1.5 V vs . RHE. Through the combination of comprehensive analysis including synchrotron X-ray absorption spectroscopy, spherical aberration-corrected high-angle annular dark field scanning transmission electron microscope as well as the density functional theoretical calculation, the efficient production of CH 4 is attributed to the coherent interface between Cu 2 O and CeO 2 , which could converted from the original CuO and CeO 2 interface, ensuring abundant active sites and enhanced intrinsic activity and selectivity towards CH 4 .