Mordenite zeolite

The dominant alteration minerals at the deeper part of the well include anhydrite, epidote, sericite, chlorite, calcite, dolomite, rhodochrosite, kutnahorite, zeolites (mordenite, clinoptilorite), chlorite and sericite/smectite interstratified clay mineral with subordinate amounts of kaolinite in the shallower part (Imai et al., 1996). 

The REAPDOR method has also been applied to zeolite mordenite [241], A relatively weak 1H-27A1 dipolar interaction was reported which translates into... 

Stability. Being a fairly high-silicious zeolite, mordenite generally has high thermal stability. It was reported (77) that progressive acid dealumination results in an increase in thermal stability, followed by a decrease. Maximum stability was reached for a Si09/Al90 ratio of about 19. 1 1 J... 

Niwa, M-, S. Kato, T. Hattori and Y. Murikami. 1984. Fine control of the pore opening size of zeolite mordenite by chemical vapor deposition of silicon alkoxide. J.C.S. Faraday Trans. 180 3135-45. 

Commercially significant zeolites include the synthetic zeolites type A (LTA), X (FAU), Y (FAU), L (LTL), mordenite (MOR), ZSM-5 (MFI), beta ( BEA/BEC), MCM-22 (MTW), zeolites E (EDI) andW (MER) and the natural zeolites mordenite (MOR), chabazite (CHA), erionite (ERl) and clinoptiloUte (HEU). Details of the structures of some of these are given in this section. Tables in each section lists the type material (the common name for the material for which the three letter code was established), the chemical formula representative of the unit cell contents for the type material, the space group and lattice parameters, the pore structure and known mineral and synthetic forms. 

Because BaO/NaX zeolite catalysts exhibited the best performance, further investigations have been carried out recently to characterize the oxidative methylation of toluene catalyzed by BaO-modified X- and Y-zeolites, mordenite, ZSM-5, sil-icalite, and ALPO4-5 (230). The authors found that activity and basicity of BaO-modified zeolites and zeolite-like catalysts depend on both the structural type and composition. Thus, for samples of the same structural type (BaO/NaX zeolite. 

Zeolite A, zeolite Y, and zeolite mordenite Size-quantized CdS and PbS formed in zeolite channels... 

Zeolite mordenite Size-quantized indium phosphide prepared in zeolite cages... 

Preparation, characterization, and photoreactivity of titanium (IV) oxide encapsulated inside sodium or ammonium exchanged zeolite, mordenite, or potassium zeolites were described 111... 

Barrer showed these hydrogen zeolites, mordenite and chabazite, to be crystalline using x-ray diffraction, and stated, Hydrogen zeolites are effectively crystalline aluminosilicic acids, the salts of which are their diverse cation exchange products." Szymanski, Stamires, and Lynch (13) used simple thermal decomposition of an ammonium zeolite X in an attempt to prepare the hydrogen zeolite... 

Zeolite catalysts in many forms are used for important commercial processes. The studies were extended to L zeolites, mordenite, erionite, and dealuminated faujasites and mordenites. More attention is paid now to zeolites with univalent and multivalent cations and to multicomponent catalysts. Among these some important examples are the tellurium-containing catalyst for hydrocarbon dehydrocyclization (42), the difunctional Ni- and Pd-zeolite catalysts for benzene hydrodimerization to phenylcyclohexane (42), the catalyst for the hydrogenation of phenol cyclohexanol (44), the 4% Ni/NaY which forms butanol, 2-ethylhexanol, 2-ethylhexanal, and 2-ethylhexanol from a mixture of n-butyraldehyde and hydrogen. 

This behavior of ZSM-5 differs considerably from that reported for the large-pore zeolites, mordenite ( ) and faujasite (2 ). With those zeolites, preferential sorption of the cycloparaffin was generally observed. 

Figure 10.12. The crystal structures of four zeolites mordenite, heulandite, laumonite, and chabazite.

Other shapes of organocations do not produce SSZ-13 and, instead, give a slower synthesis of pentasil zeolites (mordenite, ZSM-5, beta) or no conversion product at all. Hiis was observed for linear substituents on charged nitrogen. Two groups were considered (1) homologous tetraalkyl ammonium compounds and... 

In this paper we have tried to survey the catalytic properties of mordenite, making comparison where possible with faujasite-type zeolites. Mordenite shows a remarkable selectivity for n-paraffinic material in heavy distillates, and we have shown how this property might be used in a number of petroleum-refining applications. 

The catalyst used for this study is of the more recent type of dualfunction catalysts, wherein the base is a crystalline zeolite, mordenite. Palladium metal was dispersed on this support. A naphthenic isomeriza-... 

In the alkylation of benzene with long-chain a-olefins (Ce, Cg, C12, etc ), the large-pore zeolites mordenite, beta-zeolite, and ZSM-12 favor the less bulky 2-phenyl isomers. HY and rare-earth-Y produce a mixture of other -alkylbenzene isomCTS. Shiqie selectivity is attributed here to both product- and restricted transition state type selectivities [76]. 

Since the work of Lee et al. [37], zeolite mordenite continues to play an extraordinary role as a shape selective catalyst for the isopropylation of biphenyl. A high degree of dealumination [37, 38] and high pressure of propylene [39] seem to be advantageous to achieve high selectivities for 4,4 -diisopropylbiphenyl. Also, selective poisoning of the external sites with tributylphosphite [40] and the use of cerium exchanged sodium mordenites [41] are reported to suppress an undesired consecutive isomerization of 4,4 -diisopropylbiphenyl once formed in the pores. 

Figure 5.14. Al triple-quantum MAS NMR spectra of commercial zeolite mordenite in the hydrogen form, unheated and heated to various temperatures followed by hydration. Spinning side bands are marked by asterisks. The final spectrum is of a sample heated in two steps, of 650°C and 500°C with an intermediate rehydration step. After Chen et al. (2000), by permission of copyright owner.

Example 2 The effect of temperature on the crystallization of zeolite mordenite from the synthetic system 8.5 Na20-Al203-35 Si02-182H20 (Figure 3.16)... 

Table 6.4 Acid-treatment conditions of zeolite mordenite...

M. Niwa, S. Kato, T. Hattori, and Y. Murakami, Fine Control of the Pore-Opening Size of the Zeolite Mordenite by Chemical Vapour Deposition of Silicon Alkoxide. J. Chem. Soc., Faraday Trans. 1, 1984, 80, 3135-3145. 

Figure 9.14 Schematic representation of the formation of polymer from pyrrole in zeolite mordenite channels. Reproduced from [80], Copyright (2001) Elsevier...

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