Zeolite sodalite

Figure C2.12.4. Typical polyhedra found in zeolites (a) sodalite cage found in sodalite, zeolite A or faujasite (b) cancrinite or a-cage found in cancrinite, erionite, offretite or gmelinite (c) the 5-ring polyhedron found in ZSM-5 and ZSM-11 (d) the large cavity of the faujasite stmcture and (e) the a-cage fonning the large cavity in zeolite A.

Zeolite A, sodalite, zeolite X, and chabazite Size-quantized CdS formed in zeolite channels... 

Egerton and Stone (29), taking into account that synthetic sodalite zeolites did not adsorb CO molecules, concluded that CO does not enter the sodalite cages of the Y zeolites. However, the strong electric fields present in zeolites could also produce changes in the adsorptive properties of the solids thus the energies associated with the cationic sites in crystalline zeolites must be considered. From our IR results, we concluded that CO molecules were located in the volume of the sodalite cages. Thus, the steric effect alone cannot explain the different adsorptive properties exhibited by sodalite and faujasite. 

B. Beagley, J. O. Titiloye, Modeling the Similarities and Differences between the Sodalite Cages (Beta-Cages) in the Generic Materials - Sodalite, Zeolites of Type-A, and Zeolites with Faujasite Frameworks Struct. Chem. 1992, 3, 429-448. 

Figure 11.13. The composition of the sodalite cage and the structures of sodalite, zeolite A and fauja-site (zeolites X and Y).

This area also includes the introduction of additional catalytic sites in zeolites by organometallic precursor compounds. Both the adjustment of Brpnsted/Lewis acidity and the directed fixation of active transition metal centers inside zeolite cages and channels seem possible, but the size and structures of these precursors will be crucial. The molecular modification appears all the more important as many catalytic processes will remain heterogeneous in nature, especially when the shape-selectivity of sodalites, zeolites, pentasils, etc. is exploited. Once again, the possible versatility of organolanthanoid complexes deserves emphasis, since these metals verify to the above-mentioned acidity and catalysis effects [92]. 

C. Shao, X. Li, S. Qiu, and F. Xiao, The Role of Pyrocatechol as a Complex Agent for Silicon in the Synthesis of Large Single Crystals of Silica-sodalite Zeolite. Microporous Mesoporous... 

P-08 - Encapsulated guest atoms within the basic beta cage of sodalitic zeolite. A theoretical ab-initio study... 

Figure 2.5 Framework structures built up from the sodalite cage, top. Middle left to bottom right sodalite, zeolite A, zeolite Y and EMC-2. In each case only the connected locations of tetrahedral cations are illustrated. See text for a full explanation of the structures.

Most of the zeolites for which conductivity has been determined are listed in Table 14.1. Some zeolites which have only been measured in the dehydrated state have been excluded and so have others which have been reported only briefly in patents. The full list of zeolites which have been investigated as ionic conductors or which have been modified for such investigations are Analcime Zeolite A, X and Y Natrolite and Mordenite Analcime, Phillipsite, Gismondine, Sodalite, Zeolite omega. Zeolite A, X, and Y Zeolite A, X, and Y, Chabazite, Clinoptilolite and Mordenite . 

Conventional hydrothermal 8 NaOH, KOH, Na2C03 90-150 24-96 Chabazite, Na-Pl, Phillipsite, Sodalite, zeolite KH, 4A, A, P, Zeolite X, Y Low yield, low purity, structural-heterogeneity [1-5]... 

Shigemoto et al. [9] have reported about selective formation of Na-X zeolite from a mixture of coal fly ash procured from two different sources. It has been reported that most of the fly ash particles got converted into silicates and aluminates of sodium during 1 h of fusion at 773 K, whereas the hydrothermal activation for 6 h of the fused product, crystallized into Na-X, Na-A, Na-Pl and Hydroxy-sodalite zeolites in different proportions based on Na/Fly ash ratio (i.e., 1.2-1.8) employed and Al content of fly ash. It has been opined that fly ash enriched with aluminium, can be crystallized to zeolite Na-A in place of Na-X. 

F. Pascale, P. Ughengo, B. Civalleri, R. Orlando, P. D Arco and R. Dovesi. Hydrogamet defect in chabazite and sodalite zeolites A periodic Hartree-Fock and B3-LYP study. J. Chem. Phys. 117, 2002, 5337-5346. 

Tectosilicates Nepheline Analcime-leucite Felspar Sodalite Zeolite... 

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