Abstract
The versatility and accessibility of polyoxometalates have led to various applications in many fields. Especially, they are useful acid and oxidation catalysts in various reactions since its catalytic features can be controlled at a molecular or atomic level. This review summarizes recently reported types of polyoxometalate – based solid salts and liquid molten salts which are classified by the different anions. Particular attention is given to the recent research progress in the applications of POM – based ionic liquid catalysts in acid – catalyzed and selective oxidation reactions.