Understanding the Role of Functional Groups in Polymeric Binder for Electrochemical Carbon Dioxide Reduction on Gold Nanoparticles

Electrochemical CO2 reduction reaction (CO2RR) is one of the promising strategies for converting CO2 to value-added chemicals. Gold (Au) catalysts are considered to be the best benchmarking materials for CO2RR to produce CO. In this work, the role of different functional groups of polymeric binders on CO2RR over Au catalysts is systematically investigated by combined experimental measurements and density functional theory (DFT) calculations. Especially, it is revealed that the functional groups can play a role in suppressing the undesired hydrogen evolution reaction, the main competing reaction against CO2RR, thus enabling more catalytic active sites to be available for CO2RR and enhancing the CO2RR activity. Consistent with the DFT prediction, fluorine (F)-containing functional groups in the F-rich polytetrafluoroethylene binder lead to a high Faradaic efficiency (approximate to 94.7%) of CO production. This study suggests a new strategy by optimizing polymeric binders for the selective CO2RR.