A comparative study on the synthesis parameters of mesoporous MFI zeolite and the effect of temperature on the zeolite-template interaction

Abstract

MFI zeolite was synthesized using TPABr (Tetrapropylammonium bromide) and TBABr (Tetrabutylammonium bromide) templates to investigate the zeolite-template interaction and obtain the mesoporous structure of this zeolite. To achieve the lowest amount of required template, the zeolite was synthesized with TPABr with several molar compositions. The synthesized zeolite with TPABr at a temperature of 170 °C and a molar ratio of 0.2 has better crystallinity with smaller particle size. However, the zeolite synthesis with TBABr at similar condition is not successful due to the high zeolite-template interaction. Investigating the temperature effect (125–185 °C) on the zeolite-template interaction within the hydrothermal synthesis shows that the synthesis with TBABr at 140 °C reduced the zeolite-template interaction and led to successful synthesis of MFI zeolite. These crystals are less sharp, longer, and thinner than the crystals synthesized with TPABr. It has more mesoporous crystalline structure (15%) and larger pore diameter (30%) with narrow slit-like pores.