Highly Active Layered Titanosilicate Catalyst with High Surface Density of Isolated Titanium on the Accessible Interlayer Surface

Metallosilicate catalysts with tetrahedrally coordinated transition metals are attractive because of their high selectivity in the oxidation of hydrocarbons. Here, we report highly active titanosilicate catalysts featuring an isolated titanium species with a uniform tetrahedral coordination state, unusually high surface density, and high accessibility of the Ti active sites. The layered titanosilicate prepared by grafting of Ti-IV acetylacetonate onto the surfaces of the crystalline layered silicate, HUS-7, showed excellent catalytic performance in the epoxidation of cyclohexene with tert-butyl hydroperoxide as an oxidant (turnover frequency of 230 h(-1) and reaction rate of 314 mmol g(-1) h(-1)).