Active-Site Tailoring of Gold Cluster Catalysts for Electrochemical CO2 Reduction

Constructing the structure and composition of active sites of catalysts to discriminate between reaction molecules remains a grand challenge in heterogeneous catalysis, as the ability to precisely control the interfacial chemistry within molecular-scale environments is largely lacking. Here, we recognize the reaction sites of thiolate-ligand protected gold nanoclusters for CO2 electroreduction (CO2RR) by cleaving the Au-S or C-S bonds selectively that can be controlled by Cd doping. Our study reveals that the C-S bond cleavage occurring on partial ligands leads to the creation of open S sites that are able to readily bind the CO2 molecule and catalyze its reduction, while the breaking of Au-S bonds creates exposed metal sites to favor H-2 evolution that is considered as the main complete reaction of CO2RR. We further tailor the reactivities of these two types of reaction sites by only the ligand derivatization, which holds great promise in rational design of high-performance catalysts.

Automated summary

Research identified reaction sites of gold nanoclusters by selectively cleaving the Au-S or C-S bonds, showing that cleaving the C-S bonds creates open sulfur sites for CO2 reduction, while breaking the Au-S bonds favors H-2 evolution. Reactivities of these reaction sites can be further tailored by derivatizing ligands, showing promise in rational design of high-performance catalysts.