Fabrication of mesoporous solid acid catalysts with tunable surface wettability for efficient catalysis

Abstract

The sulfonic acid functionalized mesoporous silica catalysts with tunable surface wettability are fabricated by integrating a phenyl group and perfluorooctyl chain together into the pore walls of mesoporous silica materials via a prehydrolysis induced by co-condensation strategy followed by sulfonation with chlorosulfonic acid. As the content of perfluorooctyl groups increases, the water contact angle of the solid acid catalyst ranges from 15° to 95°, demonstrating that the surface properties transforms from hydrophilic to hydrophobic. These solid acid catalysts showed excellent catalytic performance in the condensation reaction of benzaldehyde with ethylene alcohol. It was found that the surface wettability influences the catalytic activity significantly and catalytic results demonstrated that a hydrophobic surface is beneficial for activity due to enhanced mass transport. It can be noted that the stability of the solid acid catalyst with hydrophobic properties could also be greatly enhanced from that of the hydrophilic solid catalyst.