Layer lattice silicates

Lateral polymerization model, 30 169-170 Lattice oxygen, 27 191, 32 118-121 chemical nature of, 27 195, 196 role of, 27 191-195 Lattice parameters, Cn/ZnO, 31 247 Layer lattice silicates, catalysts, 39 303-326 catalyst solution immobilization, 39 319-324 2-6-di-fert-butylphenoI liquid-phase oxidation on Cu -TSM, 39 322-324 propylene gas-phase oxidation on Cu Pd -TSM, 39 320-322 materials, 39 305-307 metal ion-exchanged fluorotetrasilicic mica, 39 306-308... 

Photo-oxidation reactions, 32 118 Photoreduction, metal oxides, 31 123 Phthalic acid, esterification, 17 340 Phthalocyanines EDA complexes of, 20 328-330 catalytic activity for hydrogen exchange reaction, 20 329,330 electronic configuration of, 20 330 organometallic complexes, 30 276-277 Phyllosilicates, see Layer lattice silicates, catalysts... 

Bates, T. F. (1959). Morphology and crystal chemistry of 1 1 layer lattice silicates. Amer. Min. 44 78-92. 

Aromatic radical cation formation on the intracrysta 1s surfaces of transition metal layers lattice silicates, J. Phys. Chera., 78 (1974) 994-999. 

The major subdivision of the layer lattice silicates is based upon the type of combinations of the tetrahedral and octahedral sheets. Additional subdivision is based on ... 

The three-sheet or 2 1 layer lattice silicates consist of two silica tetrahedral sheets between which is an octahedral sheet. These three sheets form a layer approximately 10 A thick. The oxygens at the tips of the tetrahedra point towards the center octahedral sheet and substitute for two-thirds of the octahedrally coordinated hydroxyls. The 2 1 clay minerals include the mica and smectite groups which are by far the most abundant of the clay minerals. The pure end members of this type are talc, a hydrous magnesium silicate pyrophyllite, a hydrous aluminum silicate and minnesotaite, a hydrous iron silicate. 

Radoslovich, E.W., 1962. The cell dimensions and symmetry of layer-lattice silicates, 2. Regression relations. Am. Mineralogist, 47 617-636. 

Figure 7.4 The cross-linked structure of a 2 1 layer lattice silicate. Oxygen atoms in the central two planes link the octahedral sheet with the tetrahedral sheets. Metal ions in the octahedral and tetrahedral positions are not shown.

Catalysis by Metal Ions Intercalated in Layer Lattice Silicates... 

Acid-treated clay minerals were employed as cracking catalysts in the first commercial process, the Houdry process, widely used in the early petroleum industries to produce high-octane gasoline. The Houdry process catalysts had been discussed extensively by many investigators (2) but were eventually completely replaced by synthetic silica-alumina or zeolite catalysts. Recently, the need for new catalytic materials has revived special interest in the layer lattice silicates because of their ion-exchange properties and their expandable layer structures. 

The catalysts preparable with swelling layer lattice silicates are classified into four types, as illustrated in Fig. 1. The intercalate of hydrated metal ion (a. Fig. 1) is easily obtained by a simple ion-exchange reaction in an aqueous medium. The intercalate acts as a Br0nsted acid catalyst because... 

Fig. 1. Catalysts preparable with layer lattice silicates.

M"+-TSM). The basal spacing of M" -TSM has been determined to be 9.6 A regardless of the interlayer metal ion M"". The metal ion-exchanged forms of the other layer lattice silicates were prepared in the same manner. 

Rg. 5. TPD specira of ammonia adsorbed on various layer lattice silicates. 

Methanol Conversion over Various Layer Lattice Silicates"... 

The results seen in Tables X and XI show that the reaction always proceeds at a considerable rate when the interlayer spacing of Cu " -TSM is expanded. This means that only a part of the metal ions is distributed on the rim of interlayer space, and the observations give a guide for improvement of the catalytic activity of metal ion-exchanged layer lattice silicates. 

Fluorotetrasilisic mica is a synthetic swelling layer lattice silicate. Because of the cation-exchange properties and the lack of acid sites on the sili-... 

Fig. 8. Reactions of methanol over metal ion-exchanged layer lattice silicates.

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