Synthesis and characterisation of super-microporous aluminosilicates prepared via primary amine templating

摘要

Super-microporous aluminosilicate catalysts, possessing pores in the range 14 ― 20A, can be prepared via primary amine templating alone or in combination with post-synthesis Al grafting. Post-synthesis grafting of extra Al also serves to remarkably improve the acidity and catalytic activity of the materials. Preparation of the super-microporous materials is made possible by circumventing the limitation on the lowest pore size obtainable, during supramolecular templating with primary amines, by improving the incorporation of Al. This is achieved by ensuring optimum dissolution of the Al source and the formation of Al-rich aluminosilicate precursors prior to addition of the primary amine template. Performing post-synthesis grafting of extra Al reduces the pore size of the resulting materials further thus increasing the possible pore size range. The super-microporous aluminosilicates are structurally as well ordered as any other primary amine templated mesoporous aluminosilicate materials.