Keggin-type P-W-Mo-V polyoxometalates in electrocatalyzed CO <sub>2</sub> reduction using indium electrodes
Yuehua Tai, Wencong Sun, Dong Yao, Li Zhou, Wenxue Tian, Haoxun Yan, Chunxiang Li
Abstract
Electrochemical CO<sub>2</sub> reduction reaction (CO<sub>2</sub>RR) driven by indium-based catalysts can convert CO<sub>2</sub> into C<sub>1</sub> 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 (H<sub>4</sub>PVMoW<sub>10</sub>O<sub>40</sub>·15H<sub>2</sub>O, PVMoW<sub>10</sub>; H<sub>5</sub>PV<sub>2</sub>MoW<sub>9</sub>O<sub>40</sub>·10H<sub>2</sub>O, PV<sub>2</sub>MoW<sub>9</sub>) to process CO<sub>2</sub>RR. The highest Faradaic efficiency (FE) toward acetate reached 75.6% in PVMoW<sub>10</sub> system and the highest FE<sub>ethanol</sub> reached 85.1% in PV<sub>2</sub>MoW<sub>9</sub> system. XPS results suggested that the electron transfer of the POMs had a positive interaction with the active site In<sup>0</sup>, which provided a special electron channel to improve the FEs of C2 products in CO<sub>2</sub>RR.