Hydrogenated mesoporous TiO2–SiO2 with increased moderate strong Brönsted acidic sites for Friedel–Crafts alkylation reaction

Abstract

The acidic properties of mesoporous TiO₂–SiO₂ mixed oxides were evaluated by ³¹P magic-angle spinning NMR spectroscopy using trimethylphosphine oxide (TMPO) and trimethylphosphine (TMP) as probe molecules. It confirms that mesoporous TiO₂–SiO₂ has moderate strong Brönsted acid sites. The number of the Brönsted acidic sites can be increased via a high-temperature hydrogenation process, which subsequently improves their catalytic performance in the Friedel–Crafts reaction of anisole and benzyl alcohol.