Synthesis and Catalytic Property of V-MCM-41 Mesoporous Molecular Sieves by Atrane Route

2011 ◽  
Vol 284-286 ◽  
pp. 936-939 ◽  
Author(s):  
Wen Ming Liu ◽  
Jia Jia Cao ◽  
Chun Ling Fan ◽  
Zhao Ping Chen
Keyword(s):  
Gas Phase ◽  
Atmospheric Pressure ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Space Velocity ◽  
Vanadium Content ◽  
Mesoporous Molecular Sieves ◽  
Active Centers ◽  
Partial Oxidation Of Toluene ◽  
Mcm 41

V-MCM-41 molecular sieve with high vanadium content has been prepared by the atrane route. Gas phase partial oxidation of toluene to benzaldehyde on the V-MCM-41 molecular sieves catalysts was studied. The structure and characteristic of catalyst were characterized by means of XRD, UV-vis and so on. The experimental results showed that the vanadium content in the framework related to mole ratio of silica to vanadium. The vanadium content in the framework was the highest, when the mole ratio of Si to V was 30. And the vanadium in the framework may be active centers of catalytic oxidation of toluene to benzaldehyde. Under the condition of atmospheric pressure, mole ratio of Si to V 30, space velocity 800 h-1, n(air):n(toluene)=5 and reaction temperature 450°C，the conversion of toluene, selectivity to benzaldehyde and its yield were 20.8%, 41.8% and 8.7% respectively.

The Effect of Type of Acid Sites in Molecular Sieves on Activity and Selectivity in Acylation Reactions

2007 ◽  
Vol 72 (5-6) ◽  
pp. 728-746 ◽  
Author(s):  
Martina Bejblová ◽  
Josef Vlk ◽  
Dana Procházková ◽  
Helena Šiklová ◽  
Jiří Čejka
Keyword(s):  
Molecular Sieves ◽  
Molecular Sieve ◽  
Acid Sites ◽  
Acid Strength ◽  
Zeolite Beta ◽  
Mesoporous Molecular Sieves ◽  
Lewis Acid Sites ◽  
Mcm 41 ◽  
Acylation Reactions

The role of the type of acid site (Broensted vs. Lewis) on the activity and selectivity of molecular sieve catalysts was investigated in ferrocene and toluene acylation. H-, Zn-, Fe-, Al- and La-forms of zeolite Beta, USY and mesoporous molecular sieves (Al)MCM-41, (Al)SBA-15 were tested. It was observed that addition of metal cations acting as Lewis acid sites can increase the acidity of various molecular sieve catalysts. No general relationship between the type of cation and conversion of individual substrate was found. While the highest activity in ferrocene acylation was observed after addition of Zn, in the case of toluene acylation Al-forms of catalysts were the most active. The results indicate that the acid strength of cationic Lewis sites controls their activity in acylation reactions.

Effect of rehydration on the porosity of MCM-41 mesoporous molecular sieves

1999 ◽  
Vol 35 (1) ◽  
pp. 52-56
Author(s):  
F. M. Bobonich ◽  
Yu. G. Voloshina ◽  
L. A. Matkovskaya ◽  
V. N. Solomakha ◽  
Yu. G. Gol’tsov
Keyword(s):  
Molecular Sieves ◽  
Mesoporous Molecular Sieves ◽  
Mcm 41

scholarly journals Hoveyda–Grubbs type metathesis catalyst immobilized on mesoporous molecular sieves MCM-41 and SBA-15

2011 ◽  
Vol 7 ◽  
pp. 22-28 ◽  
Author(s):  
Hynek Balcar ◽  
Tushar Shinde ◽  
Naděžda Žilková ◽  
Zdeněk Bastl
Keyword(s):  
Nmr Spectroscopy ◽  
Molecular Sieves ◽  
Direct Interaction ◽  
Mesoporous Molecular Sieves ◽  
Support Surface ◽  
Wall Surface ◽  
Ring Closing Metathesis ◽  
Immobilized Catalysts ◽  
Metathesis Catalyst ◽  
Mcm 41

A commercially available Hoveyda–Grubbs type catalyst (RC303 Zhannan Pharma) was immobilized on mesoporous molecular sieves MCM-41 and on SBA-15 by direct interaction with the sieve wall surface. The immobilized catalysts exhibited high activity and nearly 100% selectivity in several types of alkene metathesis reactions. Ru leaching was found to depend on the substrate and solvent used (the lowest leaching was found for ring-closing metathesis of 1,7-octadiene in cyclohexane – 0.04% of catalyst Ru content). Results of XPS, UV–vis and NMR spectroscopy showed that at least 76% of the Ru content was bound to the support surface non-covalently and could be removed from the catalyst by washing with THF.

Highly graphitic carbon nanosheets synthesized over tailored mesoporous molecular sieves using acetylene by chemical vapor deposition method

RSC Advances ◽  
2015 ◽  
Vol 5 (113) ◽  
pp. 93364-93373 ◽  
Author(s):  
Raji Atchudan ◽  
Suguna Perumal ◽  
Thomas Nesakumar Jebakumar Immanuel Edison ◽  
Yong Rok Lee
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Atmospheric Pressure ◽  
Molecular Sieves ◽  
Chemical Vapor ◽  
Graphitic Carbon ◽  
Mesoporous Molecular Sieves ◽  
Chemical Vapor Deposition Method ◽  
Deposition Method ◽  
Carbon Nanosheets

Graphitic carbon nanosheets (GCNS) were synthesized using mesoporous Ti-MCM-41 molecular sieves as catalytic template and acetylene as carbon precursor following chemical vapor deposition method, under atmospheric pressure.

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