Revolutionizing CO2‐to‐C2 Conversion: Unleashing the Potential of CeO2 Nanocores for Self‐ Supported Electrocatalysts with Cu2O Nanoflakes on 3D Graphene Aerogel

Abstract Cu serves as a promising electrocatalyst for converting CO 2 into valuable C 2 products in CO 2 reduction reactions (CO 2 RR). However, instability in CO* formation is crucial for CO 2 adsorption‐ desorption still remains a challenge under reduction conditions. This study explores the impact of lanthanide oxide, particularly CeO 2 , on Cu‐based catalytic performances. By leveraging Ce's distinctive electronic structure, CO* species are stabilized during the reaction in CeO 2 ─Cu 2 O, resulting in exceptional catalytic performance for CO 2 electroreduction to C 2 products. Hybridizing CeO 2 ‐Cu 2 O with graphene aerogel enhances electrochemical active surface area and CO 2 RR efficiency. The resulting CeO 2 ─Cu 2 O(10%)/GA electrocatalyst exhibits a remarkable faradaic efficiency for C 2 products, exceeding 62%, alongside exceptional stability over 80 h with wide potential window (−0.8 to −1.2 V) using a H‐cell. Systematic investigations elucidate the intricate interplay between surface properties and catalytic activity. Furthermore, a solar cell‐ powered CO 2 reduction system demonstrates consistent performance (−27.8 mA cm − 2 at 3.46 V) under solar radiation of ≈100 mW cm − 2 , showcasing outstanding stability with nearly 100% retention over 4 h of continuous illumination. In short, by harnessing catalytic and electronic effects, this innovation advances the development of electrocatalysts with heightened CO 2 ‐to‐C 2 selectivity, bridging fundamental research with technological innovation to tackle critical global challenges.