Heteropolyacids. Versatile green catalysts usable in a variety of reaction media

Basic characteristics of heteropolyacids as green catalysts are overviewed, focusing on the various reaction fields in which the heteropolyacid catalysts function as acid and oxidation catalysts, and then two industrial processes which were made very green by the use of heteropolyacid catalysts in liquid biphase systems are described. In this context an interesting new reaction field formed at the interfacial layer of a solid heteropolyacid and liquid has also been reported.