Ti-grafting functionalization on alkali-etched nanozeolites to enhance their catalytic performance toward oxidation desulfurization of fuels

Abstract

Using silicalite-1 and TS-1 nanozeolites as precursors, a new combination process consisting of sequential alkali-etching and Ti-grafting treatment has been designed for preparation of hierarchically structured titanosilicate catalysts. The alkali-etching process creates abundant mesopores and Si-OH groups in the nanozeolite precursors, effectively increasing the titanium loadings and accelerating the mass transfer during the reactions. Benefiting from the developed micro/mesoporous structures, the adjustable Ti loadings and the intrinsic hydrophobicity of precursor nanozeolites, the resultant catalysts demonstrate superior performance toward the catalytic oxidation desulfurization (ODS) of fuels, i.e. in 3 h, the complete conversion of thiophene (Th), benzothiophene (BT) and dibenzothiophene (DBT) which are three typical refractory sulfur compounds with diverse reducibility and molecule sizes in fuels.