CO ₂ Electroreduction to CO over Ga@Ag Core–Shell Catalysts via Interfacial Electron Modulation

The development of efficient and cost-effective catalysts for CO₂ electroreduction is of great significance for sustainable carbon utilization. Here, we report a novel Ag-coated Ga core-shell (Ga@Ag) catalyst synthesized via chemical reduction deposition, where the Ga core provides electronic modulation and the Ag shell offers abundant active sites. Structural characterizations confirm the formation of a uniform Ga(core)/Ag(shell) architecture with intimate interfacial contact, which enables strong electron coupling between Ag and Ga. Electrochemical measurements in an organic tetrabutylammonium chloride (Bu₄NCl)/acetonitrile (AN) electrolyte demonstrate that Ga@Ag exhibits a more positive onset potential, a higher CO partial current density, and a remarkable Faradaic efficiency for CO production (92.3%) at -2.4 V (vs SHE), significantly surpassing Ag powder. This work reveals that interfacial electron coupling in Ga@Ag catalysts effectively promotes CO₂ activation and enhances CO selectivity, providing new insights into the rational design of core-shell electrocatalysts for efficient CO₂-to-CO conversion under organic electrolyte conditions.