Synthesis of Zeolites in the Presence of Diquaternary Alkylammonium Ions as Structure-Directing Agents

This paper deals with the synthesis results obtained mostly from pure silica systems in the presence of (CH3 )3 N+ (CH2 )n N+ (CH3 )3 ions (n = 5 , 6, 9 or 10) in fluoride media, but also in the presence of (CH3 )3 N+ (CH2 )n O(CH2 )n N+ (CH3 )3 ions (n = 2 or 4) in hydroxide or fluoride media. A variety of zeolites form, namely ZSM-48, MTW-type, BEA-type, MFI-type, ITH-type zeolites, but also, in case of pronounced degradation of the template into N(CH3 )4 + or N(CH3 )3 , AST-type, MTN-type and RUT-type materials. The samples are characterized by XRD, SEM, thermal and elementary analyses, 1 H liquid NMR (after dissolution of the sample in HF aqueous solution) and solid-state NMR (19 F, 13 C, 27 Al) spectroscopy.