The synthesis and characterization of novel boron-containing B/Al-ZSM-12 zeolite

Abstract

In this study, new type of boron-substituted Al-ZSM-12 was developed using hydrothermal synthesis technique and methyltriethylammonium chloride as a template; physical and chemical characteristics of B/Al-ZSM-12 were studied in detail. The presence of tetrahedral boron in the isomorphically substituted zeolite was confirmed by FTIR, Raman, DRS UV–Vis, DRIFTS, 29Si and 11B NMR, and ICP–MS methods. Due to the incorporation of boron into Al-ZSM-12 zeolite, the resulting crystallites of B/Al-ZSM-12 have a shorter b-axis length compared to unsubstituted Al-ZSM-12. Moreover, boron atoms do not affect the change in the structure of Al-ZSM-12 zeolite, while being embedded in the framework, affect acidic properties, increasing total acidity and a providing high concentration of Brønsted acid sites compared to Al-ZSM-12. Meanwhile, the surface area increases from 320 m2 g−1 for Al-ZSM-12 to 350 m2 g−1 for B/Al-ZSM-12.