Abstract:

Mesoporous molecular sieves such as hexagonally ordered MCM-41 have been attracted many researchers' attention since they are potentially used as versatile catalysts and catalyst supports for conversion of large molecules. However, as compared with those of zeolites, the acidity and hydrothermal stability of these mesostructured materials are relatively low, which strongly influence their practical applications in industrial catalytic reactions of petroleum. Despite several successful examples of preparation on the stabilization of aluminosilicate mesostructures at low temperature (in boiling water,100℃) including syntheses of materials with thick pore walls by triblock copolymers, removal of silanol groups by silylation, addition of salts effects,and post-treatments, their acidity and hydrothermal stability at high temperature (800℃) are still lower than those of microporous aluminosilicate zeolites.