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.