Synthesis of Propylene Carbonate on a Bifunctional Titanosilicate Modified with Quaternary Ammonium Halides

A novel bifunctional catalyst that exhibits catalytic activity for both the epoxidation of olefins and the carbonation of organic epoxides has been prepared through grafting quaternary ammonium halide on a titanosilicate. The one-pot synthesis of propylene carbonate from propylene, hydrogen peroxide, and carbon dioxide has been investigated. Delaminated titanosilicate with an open external surface is an excellent support for the immobilization of quaternary ammonium salts, and propyl tributyl ammonium halides are active functional species for the cycloaddition. The combination of delamination and functionalization leads to an active catalyst giving a yield of propylene carbonate as high as 48% and good stability and reusability.