Octahedral molecular sieves

Yuan, J., Li, W., Gomez, S. and Suib, S.L. (2005) Shape-controlled synthesis of manganese oxide octahedral molecular sieve three-dimensional nanostructures. Journal of the American Chemical Society, 127, 14184-14185. 

Sithambaram, S., Ding, Y., Li, W., Shen, X., Gaenzler, F. and Suib, S.L. (2008) Manganese octahedral molecular sieves catalyzed tandem process for synthesis of quinoxalines. Green Chemistry, 10, 1029-1032. 

Kumar, R., Sithambaram, S. and Suib,S.L. (2009) Cyclohexane oxidation catalyzed by manganese oxide octahedral molecular sieves - effect of acidity of the catalyst. Journal of Catalysis, 262,304—313. Sithambaram, S., Kumar, R., Son, Y. and Suib, S.L. (2008) Tandem catalysis direct catalytic synthesis of imines from alcohols using manganese octahedral molecular sieves. Journal of Catalysis, 253, 269-277. 

Luo, J., Zhang, Q., Huang, A. and Suib, S.L. (2000) Total oxidation of volatile organic compounds with hydrophobic cryptomelane-type octahedral molecular sieves. Microporous and Mesoporous Materials, 35-36, 209-217. 

Green decomposition of organic dyes using octahedral molecular sieve manganese oxide catalysts. Journal of Physical Chemistry A, 113, 1523-1530. 

Abbreviations AD, asymmetric dihydroxylation BPY, 2,2 -bipyridine DMTACN, 1,4-dimethyl-l,4,7-triazacyclonane EBHP, ethylbenzene hydroperoxide ee, enantiomeric excess HAP, hydroxyapatite LDH, layered double hydroxide or hydrotalcite-type structure mCPBA, meta-chloroperbenzoic acid MTO, methyltrioxorhenium NMO, A-methylmorpholine-A-oxide OMS, octahedral molecular sieve Pc, phthalocyanine phen, 1,10-phenantroline PILC, pillared clay PBI, polybenzimidazole PI, polyimide Por, porphyrin PPNO, 4-phenylpyridine-A-oxide PS, polystyrene PVP, polyvinylpyridine SLPC, supported liquid-phase catalysis f-BuOOH, tertiary butylhydroperoxide TEMPO, 2,2,6,6-tetramethyl-l-piperdinyloxy TEOS, tetraethoxysilane TS-1, titanium silicalite 1 XPS, X-ray photoelectron spectroscopy. 

Synthesis, Characterization and Catalysis with Microporous Ferrierites, Octahedral Molecular Sieves, and Layered Materials... 

This review concerns the synthesis, characterization, and catalytic activity of microporous ferrierite zeolites and octahedral molecular sieves (QMS) and octahedral layer (OL) complexes of mixed valent manganese oxides. The ferrierite zeolite materials along with borosilicate materials have been studied as catalysts for the isomerization of n-butenes to isobutylene, which is an important intermediate in the production of methyltertiarybutylether (MTBE). The CMS materials have tunnels on the order of 4.6 to 6.9 A. These materials have been used in the total oxidation of CO to C02, decomposition of H2O2. dehydrogenation of CeHi4, C0H14 oxidation, 1-C4H3 isomerization, and CH4 oxidation. The manuscript will be divided into two major areas that describes zeolites and OMS/OL materials. Each of these two sections will include a discussion of synthesis, characterization, and catalytic activity. 

C. Synthesis Of Octahedral Molecular Sieves and Octahedral Layered Materials. 

Figure 3. Building Blocks of Octahedral Molecular Sieves.

A number of metal oxides can be described as porous materials. For instance, porous manganese oxides define octahedral molecular sieves (OMS) that have been introduced in recent years as possible materials for batteries, separations, and chemical... 

SOMS Sandia octahedral molecular sieves. A new class of ion exchangers selective for the removal of Sr " from waste streams... 

SOMS Sandia Octahedral Molecular Sieves. A new class of ion exchangers selective for the removal of Sr " from waste streams T.M. Nenoff, M. Nyman, A. Tripathi, J.B. Parise, W.T.A. Harrison and RS. Maxwell... 

An efficient oxidation catalyst OMS-1 (octahedral molecular sieve) has been prepared by microwave irradiation of a family of layered and tunnel-structured manganese oxide materials. These materials are known to interact strongly with micro-wave radiation, and thus pronounced effects on the microstructure were expected. Their catalytic activity was tested in the oxidative dehydrogenation of ethylbenzene to styrene [27]. 

The first ordered microporous transition metal oxides were microporous manganese oxides, known as octahedral molecular sieves (OMS). The manganese oxide OMS are classified into three families the pyrolusite-ramsdellite family with a (1 x n) channel structure the hollandite-romanechite family with a (2 x n) channel structure ... 

Figure 3.1 Structure and pore of manganese oxide octahedral molecular sieves (OMS) (a) todorokite (3x3) channel (b) romanechite (2x3) channel and (c) hollandite (2 x 2) channel...

Inorganic molecular sieves in which all of the framework cations are coordinated octahedrally comprise a small but significant family of microporous solids. The octahedral molecular sieves, or OMS materials, related to manganese oxide minerals of the hollandite family, are the most important of these. Examples have been prepared by Suib and co-workers through the hydrothermal treatment of layered manganese oxides. Careful choice of additional metal ion content of such preparations controls the inorganic phase that forms. The... 

Further to the synthesis of the OMS materials, researchers at Sandia National Laboratories reported the synthesis of a family of microporous niobates, general formula Na2Nb2 xM 06 x(0H)x.H20 (M = Ti, Zr x = 0.04-0.40), prepared from hydrothermal treatment of intimately mixed metal alkoxide precursors. The structure is made up of layers of edge-sharing octahedra interleaved with double ehains of edge-sharing niobate octahedra, in which additional, hydrated sodium eations reside. The niobate chains exhibit solid substitution. These SOMS (Sandia octahedral molecular sieves) demonstrate appreciable ion exchange eapacity and are selective for divalent cations. 

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