Layer lattice silicates, catalysts

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... 

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.

The immobilization of metal complex catalysts on polymers and inorganic oxides has received considerable attention as a means of combining the best advantages of homogeneous and hetereo-geneous catalysis (1-6). The swelling layer lattice silicates known as smectite clay minerals have added an important new dimension to metal complex Immobilization. These compounds have mica-type structures in which two-dimensional silicate sheets are separated by monolayers of alkali metal or alkaline earth cations (7). The structure of a typical smectite, hectorite, is illustrated in Figure 1. 

The first most significant papers in the literature, which investigated the potential of layered silicates as possible host lattices of active catalysts for the synthesis of polyolefin nanocomposites, were reported by O Hare, Mulhaupt, and Garces. O Hare et al. used ion exchange to intercalate cationic metallocene species into clay interlayer galleries, followed... 

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