Other microporous solids

Karger, J Ruthven, DM, Diffusion in Zeolites and Other Microporous Solids Wiley New York, 1992. 

Adachi-Pagano, M., Forano, C. and Besse, J.-P. (2003) Journal of Materials Chemistry, 13, 1988-1993. de Roy, A., Forano, C., El Malki, M. and Besse, J.-P. (1992) Synthesis of Microporous Materials, inExpanded Clays and Other Microporous Solids... 

Clays and Other Microporous Solids. Chapter 7, Synthesis of Macroporous Microp-... 

A. Sayari, V.R. Karra and J. Sudhakar Reddy, Symposium on Synthesis of Zeolites, Layered compounds and other Microporous Solids, 209 National Meeting, Am. Chem. Soc. Anaheim (1995). 

Karger, J., and Ruthven, D. M. (1992) Diffusion in Zeolites and other Microporous Solids, John Wiley Sons, New York. 

J. KSrger, and D.M. Ruthven, Diffusion in zeolites and other Microporous solids (John Wiley, New York, 1992). 

Karger, J. Ruthven, D.M, Diffusion in Zeolite and other microporous solids, John Wiley Sons, 1992... 

M.L Occeili and H. Robson (eds.). Synthesis of Microporous Materials Expanded Clays and Other Microporous Solids, Vol. II, Van Nostrand, 1992. 

Table I shows a set of numerical data concerning the surface, the density, and the total pore volume of the different catalysts used. These values are completed by the spectrometry of the pores. For example, Fig. 1 (plain lines) shows the variation of total pore volume (Fp) as a function of pore radius (r), measured in angstroms in the case of microporous solids of the CSU, CAU, and ECU type. The dotted line, corresponding to a CAU type, shows pore distribution as a function of pore radius, the maxima permitting the evaluation of those pores which occur most frequently in the microporous structure. In the example chosen, the pores of approximately 35 A. are the most frequent ones. Another very important maximum is located at 300 A. Similar studies were made for the other microporous solids. In the case of silica (CS and CSU), a maximum number of micro-...

In the structures of several other microporous solids, including porosils, AlPOs and GaPOs, that were synthesized by the fluoride method, the fluoride anion was found in a different location than in [Co(cp)2]-NON, i.e., not directly bonded to one of the framework atoms. Instead, it occupies the center of a double four-ring unit. An example is another porosil of AST structure, namely quinuclidinium-AST [53]. Therefore, it has been supposed that the F" anion acts as a co-template, stabilizing structures that contain double four-ring units [23]. In agreement with this idea, we find that AST is only formed in fluoride-containing syntheses, and not in fluoride-fi-ee preparations. 

There are other microporous solids that are not aluminosilicates hence, they are not zeolites. The titanosili-cates, such as titanium silicalite (TS-1), which are selective catalysts for oxidations, are discussed in Chap. 4. Much work is going into extending these findings to materials with larger pores to accommodate larger substrates for oxidation. Molecular sieves also include the aluminum phosphate (AIPO) family.145 These have been modified by inserting a variety of cations into them, including... 

The molecular-sieve zeolites are distiact from other three major npore size. Although other microporous solids are used as adsorbents for the separation of vapor or liquid mixtures, the distribution of pore diameters does not enable separations based on the ssolecular-sieve effect, that is. sepurations caused by difference in the molecular size of the materials to be separated. The most impurtanr molecular-sieve effects are shown by dehydrated crystalline zsoliles. Zeolites selectively adsorb or reject molecules based on differences in molecular size, shepe. and other properties such as polarity. Daring the ndsorption of various molecules, the micropores fill and empty reversibly. Adsorption in zeolites is a matter of pore filling, and the usual surface-area concepts are not applicable. 

Another historically important area involving inorganic chemistry in hydro-thermal fluids is related to the synthesis of zeolites and other microporous solids. It was recognized early on that naturally occurring zeolites (or boiling stones) are the result of natural hydrothermal activity. Thus, a fairly intense effort to prepare new zeolites from hydrothermal solutions in the laboratory was mounted, particularly in the petrochemical industry. Much of the early work is summarized in an excellent monograph by Barrer [29]. Most of the useful microporous solids are prepared at relatively low temperatures... 

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