New Route to Pentasil-Type Zeolites Using a Non Alkaline Medium in the Presence of Fluoride Ions

Synthesis of Core-shell Structured Porous Materials and Applications as Catalysts and Precursors for Hollow Porous Materials

“…On the other hand, core synthesis using fluoride ion (CF(C)) resulted in no formation of mesopores. These results are consistent with the findings of previous studies 15), 16) . During second hydrothermal synthesis on CF(C) and CF(NC) cores in the presence of fluoride ion, the particles grow from 15 to 18 μm along major axis (Table 1), strongly suggesting that crystal overgrowth occurs on the core particles during the second synthesis.…”

Hydrothermal synthesis and characterization of microporous crystals of trivalent metal-containing zirconium phosphates

“…The bending modes of the -CH 2 -groups in the 1,6-diaminohexane appear around 1400 cm −1 . The broad band is observed in the region 1100-900 cm −1 , and they correspond to the asymmetric stretching vibrations of PO 4 units. An absorption at 560 cm −1 appears as well, which is due to bending vibrations of phosphate groups [19][20][21][22] appear at 3570, 3200, 3050, 2854, 2360, 1600, 1544, 1422, 1050, 635, 559 and 444 cm −1 .…”

“…Among them, zirconium phosphates are very attractive materials for their applications in ion exchange, intercalation, ion conductivity, catalysis and molecular sorption [2,3]. Since the use of fluoride ions as mineralizers was introduced by Guth et al [4] into hydrothermal preparation of zeolite, a good number of metal phosphate fluorides have been obtained. Recently, the fluoride route has led to the first zirconium phosphate (ZrPO-1) with three-dimensional open-framework structure [5].…”

Time-resolved powder diffraction as an analytical tool for diffusion studies in microporous topologies

“…The unit-cell content of the starting material corresponds to the formulation 0021-8898/88/030266-06503.00 © 1988 International Union of Crystallography H3.22B3.2oAlo.o28i92.780192. This phase is produced from the calcination of the as-synthesized form corresponding to sample reference ACF273 prepared by Wey's group (Guth, Kessler & Wey, 1986). The different M FI/sorbate systems have been prepared by pouring directly the just-calcined (24 h at 823 K) and nearly cooled samples in airtight bottles (10 ml capacity) containing an excess of the liquid sorbate (e.g.…”