Dry synthesis of B-MFI, MTN- and MTW-type materials

Abstract

B-MFI and MTN-type materials were synthesized via the fluoride route from dry powders in the complete absence of a solution phase. Amorphous precursors obtained by drying SiO₂ · Al₂O₃ gels at 700°C were transformed into MTN-type material in the presence of dried NH₄F and TMACl. Amorphous precursors obtained by drying SiO₂ gels at 700°C were transformed into B-MFI in the presence of dried NH₄F, B₂O₃ and TPABr. Water is formed as a reaction product. However, the water vapor pressure is appreciably below the water vapor saturation pressure under the given reaction conditions. In addition, syntheses using seed crystals were carried out successfully.