Mediating CO2 Electroreduction Activity and Selectivity over Atomically Precise Copper Clusters

Atomically precise copper clusters are highly desirable catalysts for electrocatalytic CO2 reduction reaction (CO2RR) and provide an ideal platform for elaborating structure-activity relationships. However, systematic comparative studies of Cu cluster isomers for electrocatalytic CO2RR are lacking because they are challenging to synthesize. A group of structurally precise Cu-8 cluster isomers with different core structures (cube- and ditetrahedron-shaped) were developed and investigated for highly active and selective CO2 reduction. Electrocatalytic measurements showed that the ditetrahedron-shaped Cu-8 cluster exhibited a higher FEHCOOH (approximate to 92 %) at -1.0 V and higher selectivity than the cube-shaped cluster. Theoretical investigations revealed different levels of competitiveness with the hydrogen evolution reaction on the respective core-shaped Cu-8 clusters and decreased free energies for the adsorbed HCOO* intermediates on the ditetrahedron-shaped Cu-8 clusters.