A novel and recyclable catalytic system for propylene carbonate synthesis from propylene oxide and CO2

A novel and recyclable catalytic system composed of Zn[bis(2-hydroxybenzene)phthaldimine] [Zn(BHBPDI)] and tetrabutylammonium bromide (TBAB) was developed to catalyze the coupling reaction of CO2 and propylene oxide to yield the cyclic carbonate. The different parameters had been investigated. Nearly 100% selectivity and 100% yield of propylene carbonate was achieved under the optimized reaction conditions. The [Zn(BHBPDI)] could be easily recovered and reused for many times. The activity of the catalytic system decreased obviously after nine recycles, but the activity was restored by adding an amount of TBAB to the reaction mixture. On the basis of the experimental results, the mechanism for the reaction was proposed. (c) 2011 Elsevier Ltd. All rights reserved.