Cobalt doping regulated Ag electronic structure for boosting electroreduction of CO2 to CO at gas-solid interface

Abstract

Electroreduction of gas-phase CO₂ (CO₂RR) to CO is an attractive way to promote sustainable and carbon-neutral economic development. The Ag-based catalysts have demonstrated great potential for CO₂RR to CO reaction. Herein, we showed that the Co-doping into Ag catalyst significantly enhanced the performance of CO₂RR. Compared with pure Ag catalyst, the FE_CO for Ag-Co bimetallic catalyst was increased by nearly 30%, reaching 95.3% with high stability at the full-cell potential of −2.1 V in the gas-phase electroreduction system. Based on physicochemical characterizations, we confirmed that the specific Ag-Co bimetallic structure was formed, the interaction between Ag and Co metals increased the electrochemically active surface area and exposed more adsorption and reactive sites. Combined with the DFT calculation results, we revealed that the Co doping regulated the electronic structure around Ag sites, and more electrons transferred from Co to Ag sites, promoting the CO₂ adsorption and the formation of key intermediates (*COOH) on catalyst surface, therefore leading to a higher performance for CO₂RR to CO.