Keggin type phosphotungstic acid is also called phosphotungstic heteropoly acid, normally this type belongs to twelve phosphotungstic acid, as a solid acid, it can be used as catalyst in organic catalytic reactions. Different crystal water content cause difference in color, it can be light yellow or white powder. It is easy dissolved in water, ethanol and ether. In laboratory, isolating phosphotungstic acid solution often use ether extraction. It can produce yellow emulsions after reacting with concentrated hydrochloric acid.
Phosphotungstic acid having a tertiary structure: anionic primary structure, secondary structure of crystalline acid salt anions and counter ion combinations, polyanionic, the tertiary structure of counter ions consisting of three parts, with the crystalline water.
It can be applied in Friedel-Crafts alkylation and acylation, esterification, dehydration / recombination reactions, redox reactions, asymmetric catalysis, isomerization reaction, the cleavage reaction, as well as open-loop, condensation, addition and etherification.