Enhanced Active Hydrogen Absorption and Stabilized Cu(I) Species Over Cu‐O‐Ce Bridges Boosting Electrocatalytic CO 2 Reduction to Ethylene

Abstract Rational design of water activation center to promote active hydrogen (*H) generation and stabilize Cu(I) species are significant for the formation of multicarbon (C 2+ ) products over Cu‐based catalysts in electrocatalytic CO 2 reduction reaction (CO 2 RR). Herein, CeO 2 nanograins and CuO nanothorns were selectively deposited on the edges of Cu 2 O cubes through the seed‐mediated growth method. The as‐synthesized Cu x O–CeO 2 composites exhibit enhanced Faradaic efficiency and partial current density of C 2 H 4 compared with Cu 2 O cubes. In situ spectroscopies and theoretical calculations confirm that the Cu–O–Ce bridges in Cu x O–CeO 2 composite can effectively enhance *H absorption and stabilize Cu(I) species, facilitating subsequent C–C coupling and further protonation into the key *COCHO intermediate of C 2 H 4 . This work provides new insights into modulating *H absorption and stabilizing Cu(I) species for boosting CO 2 to C 2+ products.