Direct room-temperature synthesis of methyl-functionalized Ti-MCM-41 nanoparticles and their catalytic performance in epoxidation

Methyl-functionalized Ti-MCM-41 nanoparticles with a size of 80 to 160 nm (Me-Ti-MCM-41 NP) were directly prepared via a dilute solution route by the co-condensation of tetraethoxysilane and methylalkoxysilanes in sodium hydroxide medium at room temperature. The characterization results showed the e...

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Vydáno v:Journal of catalysis Ročník 263; číslo 1; s. 75 - 82
Hlavní autoři: Lin, Kaifeng, Pescarmona, Paolo P., Houthoofd, Kristof, Liang, Duoduo, Van Tendeloo, Gustaaf, Jacobs, Pierre A.
Médium: Journal Article
Jazyk:angličtina
Vydáno: Amsterdam Elsevier Inc 01.04.2009
Elsevier
Elsevier BV
Témata:
Aqueous H 2O 2
Catalysis
Chemical synthesis
Chemistry
Colloidal state and disperse state
Dilute solution route
Epoxidation of cyclohexene
Exact sciences and technology
General and physical chemistry
Methyl-functionalized Ti-MCM-41 nanoparticles
Molecular structure
Nanoparticles
Physical and chemical studies. Granulometry. Electrokinetic phenomena
Porous materials
Shorter mesoporous channels
tert-Butyl hydroperoxide
Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
Dilute solution route
Shorter mesoporous channels
Aqueous H 2O 2
Methyl-functionalized Ti-MCM-41 nanoparticles
Epoxidation of cyclohexene
tert-Butyl hydroperoxide
Water
Particle size
Hydrogen peroxide
Nanoparticle
Washing
Selectivity
Condensation
Porous material
Sodium hydroxide
Characterization
Particle
Synthesis
Dilute solution
Epoxidation
Aqueous H2O2
Structure
Catalytic reaction
Organic hydroperoxide
Reaction rate
Mesoporosity
Hydrolysis
Heterogeneous catalysis
Regeneration
Epoxide
Frequency
Methylation
Ethylenic compound
Catalyst
Room temperature
ISSN:0021-9517, 1090-2694
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Shrnutí:Methyl-functionalized Ti-MCM-41 nanoparticles with a size of 80 to 160 nm (Me-Ti-MCM-41 NP) were directly prepared via a dilute solution route by the co-condensation of tetraethoxysilane and methylalkoxysilanes in sodium hydroxide medium at room temperature. The characterization results showed the existence of ordered hexagonal mesoporous structure and tetrahedral Ti species in the nanoparticles. In the epoxidation of cyclohexene with tert-butyl hydroperoxide and aqueous H 2O 2, Me-Ti-MCM-41 NP samples displayed higher turnover frequencies (TOFs) for cyclohexene and initial reaction rates compared to Ti-MCM-41 and methyl-functionalized Ti-MCM-41 with normal particle size and to non-functionalized Ti-MCM-41 nanoparticles. Simultaneously, a higher selectivity for cyclohexene epoxide was observed in the case of aqueous H 2O 2, suggesting that the hydrolysis of cyclohexene epoxide with water is reduced on Me-Ti-MCM-41 NP samples. The improved catalytic behavior of Me-Ti-MCM-41 NP is discussed both in terms of the nanosize and methylation of the surface of the catalyst particles. The regeneration of Me-Ti-MCM-41 NP with tert-butyl hydroperoxide solution was evaluated via washing and calcination approaches. Methyl-functionalized Ti-MCM-41 nanoparticles display improved catalytic performance in the epoxidation of cyclohexene.
Bibliografie:SourceType-Scholarly Journals-1
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content type line 14
ISSN:0021-9517
1090-2694
DOI:10.1016/j.jcat.2009.01.013