Sulfated mesoporous Au/TiO2 spheres as a highly active and stable solid acid catalyst

Abstract

In this work, we reported several kinds of highly stable, effective mesoporous Au/TiO₂ sphere-based solid acid catalysts with large specific surface areas and good monodispersity in the reaction medium. In this process, monodisperse titanium glycolate spheres were first formed by an antisolvent precipitation route, and were then converted to mesoporous TiO₂ by in situ hydrolysis under hydrothermal conditions. The resultant uniform TiO₂ spheres were subsequently functionalized with sulfate anions at different temperatures or incorporated with tungstophosphoric acid (TPA); the solid acid catalysts were thus fabricated. In particular, our monodisperse spherical catalysts with large specific surface area have shown remarkable performance in a wide range of acid-catalyzed reactions such as Friedel–Crafts alkylation, esterification and hydrolysis of acetate. The TiO₂-based catalysts could be separated and reused showing no deactivation.