Keggin type P-W-Mo-V POMs in collaboration with indium electrode electrocatalyzed CO 2 reduction

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