Keggin type heteropolyacid, preparation method thereof and application of Keggin type heteropolyacid in carbon reduction

The invention discloses Keggin type heteropolyacid as well as a preparation method and application thereof in carbon reduction, and relates to heteropolyacid as well as a preparation method and application thereof. The invention aims to solve the problems that CO2 electrocatalytic reduction products realized on the basis of Keggin type heteropolyanions at present are concentrated in synthesis gas, the reduction depth is relatively low, a carbon product is a gas phase and can be mixed with unreacted reactants CO2, air and the like, the separation difficulty is relatively high, and the high Faraday efficiency of ethanol cannot be realized. The method comprises the following steps: 1, dissolving disodium hydrogen phosphate in deionized water, then adding sodium molybdate, carrying out heating reaction, then adding sodium metavanadate, and carrying out stirring reaction to obtain a mixed solution; 2, adding absolute ether, oscillating and extracting to obtain red oil droplets; and 3, adding 49-50% by mass of dilu