Construction of coherent interface between Cu₂O and CeO₂via electrochemical reconstruction for efficient carbon...

Developing an efficient electrocatalyst that enables the efficient electrochemical conversion from CO₂ to CH₄ across a wide potential range remains a formidable challenge. Herein, we introduce a precatalyst strategy that realizes the in situ electrochemical reconstruction of ultrafine Cu₂O nanodomains, intricately coupled on the CeO₂ surface (Cu₂O/CeO₂), originating from the heterointerface comprised of ultrafine CuO nanodomains on the CeO₂ surface (CuO/CeO₂). When served as the electrocatalyst for the electrochemical CO₂ reduction reaction, Cu₂O/CeO₂ delivers a selectivity higher than 49 % towards CH₄ 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 CH₄ 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 CH₄ is attributed to the coherent interface between Cu₂O and CeO₂, which could converted from the original CuO and CeO₂ interface, ensuring abundant active sites and enhanced intrinsic activity and selectivity towards CH₄.