Keggin-type P-W-Mo-V polyoxometalates in electrocatalyzed CO2 reduction using indium electrodes

Abstract

Electrochemical CO2 reduction reaction (CO2RR) driven by indium-based catalysts can convert CO2 into C1 products with specific energy densities and relatively low mass. However, it is promising to obtain C2 products by introducing Keggin-type polyoxometalates (POMs) that can effectively regulate the proton-coupled electron transfer at the electrode–electrolyte interface. Here, the commercial indium sheets were combined with Keggin-type POMs (H4PVMoW10O40·15H2O, PVMoW10; H5PV2MoW9O40·10H2O, PV2MoW9) to process CO2RR. The highest Faradaic efficiency (FE) toward acetate reached 75.6% in the PVMoW10 system, and the highest FEethanol reached 85.1% in the PV2MoW9 system. The X-ray photoelectron spectroscopy (XPS) results indicated that the electron transfer by the POMs had a positive interaction with the active In0 sites, which provided a special electron channel to improve the FEs of the C2 products in CO2RR.

Keywords

• polyoxometalate
• electrochemical co2 reduction reaction
• indium
• acetic acid
• ethanol