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 and100% 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.

Graphical abstractA novel and recyclable catalytic system of Zn[bis(2-hydroxybenzene)phthaldimine] with tetrabutylammonium bromide was developed to catalyze the reaction of CO2 with propylene oxide under mild conditions.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The novel and recyclable catalytic system Zn(BHBPDI)/TBAB was developed. ► The reaction conditions were optimized. ► The catalyst could be easily recovered and reused. ► The reaction mechanism was proposed.