Constraint of Reaction Intermediates in Ag@Cu ₂ O Porous Core–Shell Nanospheres Toward Boosted CO ₂ Electroreduction to C ₂ H ₄

At present, Cu-based catalysts have problems such as low current density and low selectivity of products during the electrochemical reduction of CO₂. Herein, a porous core-shell structure Ag@Cu₂O catalyst is constructed by an in situ growth method, where a layer of Cu₂O is encapsulated outside Ag. The catalyst is promoted to generate CO by Ag with a lower energy barrier, and the porous Cu₂O shell accelerates the diffusion of CO₂ molecules and electrolyte through its continuous pores, while the physical confinement effect prolongs the residence time of CO intermediates on the surface of Cu₂O, promoting CC coupling. Ag@2Cu₂O demonstrates a 63% C₂H₄ Faradaic efficiency at an electrode potential of -1 V vs reversible hydrogen electrode. Moreover, the mechanical flexibility and stress buffering capacity of the porous structure enable the catalyst to maintain structural integrity during continuous operation for up to 12 h.