A heteropolyacid-based ionic liquid as a thermoregulated and environmentally friendly catalyst in esterification reaction under microwave assistance

A new kind of heteropolyacid (HPA) ionic liquid [(CH3)(3)NCH2CH2OH]H2PW12O40 (ChH(2)PW) has been synthesized using choline chloride and H3PW12O40 (HPW) as precursors. The catalyst exhibited a novel switchable property based on temperature. The separation of the catalyst would be explored by simply decreasing reaction temperature without appreciable loss. Excellent conversions (97%) for esterification have been obtained under microwave-accelerated conditions. (C) 2013 Elsevier B.V. All rights reserved.