20-09-2017, 03:37 PM
The reaction of epoxides and carbon dioxide to corresponding cyclic carbonates using silica supported polyvinylpyridine as a highly active heterogeneous base catalyst has been described. The typical optimized PVP / SiO2 catalyst can be prepared from 10% by weight of PVP filler using surface silica of 800 m2 g -1. The reaction gives a yield of 91% of propylene carbonate at 5.5 MPa of CO2 pressure, 150 ° C and 6 h. The catalyst was found to be recyclable in four recycles without any loss in catalytic activity.