Secondary Synthesis and Characterization of Boron-Containing ZSM-5 Zeolites

Under conditions of secondary synthesis and to varying extents, boron can be incorporated into the tetrahedral framework sites of a ZSM-5 zeolite which has been synthesized template-free or in the presence of organic template compounds and subjected to calcination or hydrothermal treatment. Isomorphic incorporation of boron is verified by means of ¹¹B MAS NMR measurements and it is reflected in a contraction of the unit cell volume of the zeolite lattice. A comparative study of the catalytic properties of the boron-containing ZSM-5 in acid catalysed n-hexane cracking revealed that samples based on template synthesis product are more active and show less tendency to deactivation.