Synthesis and crystal structure of layered silicate PLS-3 and PLS-4 as a topotactic zeolite precursor

Synthesis of Gallosilicate Type Molecular Sieve with CDO Topology and Application to Solid Acid Catalyst

“…They have claimed that the CDS-1 zeolite was prepared from the layered silicate precursor denoted as PLS-1 by calcination via topotactic dehydrative condensation and that the hydrothermal synthesis including an organic additive in the starting gel successfully provided the corresponding PLS-1 crystalline. Recently, they have also developed the synthetic strategy utilizing protonated kanemite as a silica source, resulting in a facile access for preparing PLS-1 and its isomorphous analogues 23) . The characteristic synthetic feature of the CDS-1 zeolite forming via layered zeolite precursor gives us an opportunity for extended researches such as MCM-22 and PREFER 24) .…”

Layered zeolitic materials: an approach to designing versatile functional solids

“…The PREFER has also been obtained from layered silicate H-kanemite as silica source and tetramethylammonium hydroxide as structure directing agent, being called in this case PLS-3. 45,46 Within the PREFER zeolitic precursors, Lobo et al synthesized the MCM-47 zeolite from its corresponding layered material, 47 following previous studies reported by Szostak et al and Valyocsik et al 48,49 Specifically, di-quaternary ammonium salts prepared from 1-methylpyrrolidine and 1,4-dibromebutane were used as specific structural directing agents. The lamellar precursor of MCM-47 is analogous to PREFER except for a slight displacement, along the b axis and half unit cell displacement in the spatial situation of ferrieritic layers is detected from structural resolution studies ( Figure 6).…”

Synthesis of germanosilicate type CDS-1 zeolite with CDO topology and its zeolitic layered precursor

“…Synthetic strategy of CDS-1 zeolite is quite unique than conventional hydrothermal syntheses, that is, it can be prepared from the corresponding layered silicate PLS-1 by the calcination via topotactic dehydrative condensation, and the layered zeolite precursor PLS-1 is able to be prepared by the hydrothermal synthesis in the presence of 1,4-dioxane as an organic additive [1]. Recently the improved synthetic procedure of PLS-1 and its analogues has been reported by utilizing an acidified kanemite (H-kanemite) as a silica source in the restricted amount of H 2 O [3], offering a facile access for preparing PLS-1 and its layered silicate analogues.…”

“…So far, the isomorphic materials of PLS-1 such as MCM-65, UZM-13, UZM-17, Nu-6(1), EU-19, RUB-18, RUB-39 and PLS-4 have been introduced by many researchers [3][4][5][6][7][8][9][10][11][12]. Among these materials, the PREFER (layered precursor of ferrierite) has been interestingly investigated [13][14][15][16][17], in particular, the delaminated PRE-FER (ITQ-6) [18,19] has applied for catalysts and novel supports as a nano-sheet silicate [20][21][22][23][24][25].…”