Selective electroreduction of CO2 to formate by polythiophene/copper composite catalysts
Polythiophene(PTh)and polycrystalline Cu nanoparticles were successively electrodeposited on a gas diffusion layer(GDL)to catalyze the electroreduction of CO2 to formate(HCOO-).The Faradaic ef-ficiency(FE)for HCOO-can reach up to 88%,higher than the FE of 74%in the absence of PTh.The superior selectivity can be attributed to two factors.One is the PTh layer that can create a hydrophobic en-vironment around the gas-liquid-solid interface thus suppressing hydrogen evolution reaction.The other one is the Cu—S bonds formed at the PTh/Cu interface,which can favor the desorption and reduction of the intermediate HCOO*to form the stable product HCOO-.This work provides a new insight for the de-signing of Cu-based electrocatalysts to convert CO2 to HCOO-with high selectivity.