The polymeric quaternary ammonium salt supported on silica gel as catalyst for the efficient synthesis of cyclic carbonate

Abstract

A polymeric quaternary ammonium salt, polydiallyldimethylammonium bromide (PDDA-Br), was supported on silica gel and employed as a recyclable heterogeneous catalyst for the catalytic synthesis of cyclic carbonate. The supported catalysts had been characterized by FT-IR, XRD, TGA and SEM methods. It was observed that PDDA-Br, silica and Lewis acid exhibited strong synergistic effect for the cycloaddition reaction. The addition of Lewis acid like ZnBr2, ZnCl2 and FeCl3 AlCl3 would improve the catalytic activity significantly. Especially, the combination of PDDA-Br with ZnBr2 afforded the most efficient catalyst for the cycloaddition reaction. Silica gel has high BET surface area and allowed good dispersion of PDDA-Br and ZnBr2. Moreover, the as-prepared catalyst was highly stable and leaching-resistance. It could be reused at least 10 times without any loss of activity.