Heteropolyacids. Versatile green catalysts usable in a variety of reactionmedia

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