Characterization of siliceous MFI-type zeolites containing tetra-, tri-, and dipropylammonium fluoride species

Abstract

Highly siliceous MFI-type zeolites containing tetra-, tri-, and dipropylammonium fluoride species, synthesized in the presence of fluoride ions, were characterized by powder X-ray diffraction t.g., d.s.c., and high-resolution solid-state n.m.r. of 13C and 29Si. The occupation of the channels by the different organic species could be elucidated by considering the refined unit cell parameters. In the case of, particularly, the dipropylammonium fluoride-containing sample the organic molecule is found to be located preferentially in the zigzag channels, in agreement with the results of the other techniques.