Gold Adparticles on Silver Combine Low Overpotential and High Selectivity in Electrochemical CO2 Conversion

Silver (Ag) catalysts enable high selectivity (>90%) in CO2-to-CO conversion at >100 mA cm(-2); gold (Au) catalysts are active at lower overpotential, but with lower selectivity (<80%). Here we present an adparticle-functionalized catalyst that combines the benefits of each by uniting Au adparticles on the AgAu interface. Au adparticles modify the lattice and electronic structure of Ag and lower the free energy change required to form *COOH. We demonstrate selective and low-overpotential CO2-to-CO conversion at >490 mA cm(-2) in a flow cell. In a membrane electrode assembly, the catalyst achieves 90% CO selectivity and 33% CO energy efficiency over 60 h.

Automated summary

This study presents a novel adparticle-functionalized catalyst that combines the advantages of silver (Ag) and gold (Au) catalysts by uniting Au adparticles on the AgAu interface. The Au adparticles modify the lattice and electronic structure of Ag, leading to selective and low-overpotential CO2-to-CO conversion. The catalyst demonstrates high selectivity and efficiency in both a flow cell (>490 mA cm(-2)) and a membrane electrode assembly (90% CO selectivity and 33% CO energy efficiency over 60 h).