
Phosphotungstic heteropoly acid, also called Keggin type phosphotungstic acid, belongs to twelve phosphotungstic acid with the formula of H3PW12O40?nH20. It is a light yellow crystal or white powder. Different crystal water content cause difference in color. It is generally light yellow if it contains more crystal water; otherwise, it is white powder. It is soluble in water, alcohol, and ether, etc. Its solubility reaches the highest in ether. Keggin type phosphotungstic acid, as a solid acid with excellent catalytic performance,…