Results 241 to 250 of about 24,536 (272)

Characterisation and catalytic properties of MCM-41 and Pd/MCM-41 materials

Catalysis Letters, 1997
Pure silica MCM-41 mesoporous molecular sieve material was synthesised and characterised by in situ synchrotron XRD, TEM, TGA/DTA and DRIFTS techniques. In situ energy dispersive XRD (EDXRD) confirmed the exact nature of the pore diameter of MCM-41 and the change in crystal structure on calcination. The IR band at 1057 cm-1 of as-synthesised MCM-41 was
C.A. Koh, R. Nooney, S. Tahir
openaire   +1 more source

Characterization of hydrothermally treated MCM-41 and Ti-MCM-41 molecular sieves

Catalysis Today, 2004
In this work we report the characterization and results of hydrothermal treatment tests performed on MCM-41 and Ti-MCM-41 materials at two temperatures, 450 and 550 °C. Based on BET analyses and XRD measurements, results showed a decrease in specific surface area, pore volume and pore size for both materials after the hydrothermal treatments.
P. Schacht, L. Noreña-Franco, J. Ancheyta, S. Ramírez, I. Hernández-Pérez, L.A. García   +5 more
openaire   +1 more source

Photovoltaic activity of Ti/MCM‐41

ChemPhysChem, 2009
AbstractTi/MCM‐41 is a well‐known heterogeneous catalyst for alkene epoxidation with organic peroxides. This titanosilicate contains isolated titanium atoms forming part of a framework of mesoporous silica whose structure is formed by parallel hexagonal channels 3.2 nm in diameter.
Pedro, Atienzar, Maite, Navarro, Avelino, Corma, Hermenegildo, Garcia   +3 more
openaire   +2 more sources

H3PW12O40 supported on mesoporous MCM-41 and Al–MCM-41 materials: preparation and characterisation

Journal of Materials Science, 2011
MCM-41 and Al–MCM-41 has been synthesized using cetyl-trimethylammonium bromide (CTAB) surfactant as template and adding the silica precursor to aqueous solutions containing CTAB. The obtained solids were calcined at 600 °C for 4 h. HPW heteropolyacid supported on the mesoporous were prepared using the incipient wetness method.
Kraleva, E, SALADINO, Maria Luisa, SPINELLA, Alberto, NASILLO, Giorgio, CAPONETTI, Eugenio   +4 more
openaire   +2 more sources

Flexibility of the MCM-41 structure: pore expansion and wall-thickening in MCM-41 derivatives

Applied Catalysis A: General, 2002
Utilizing the flexibility of the structure of MCM-41 type mesoporous metal silicates pore size modification was successfully performed for some MCM-41 samples including materials which contain Al or Ti heteroatoms in the wall or organic modifiers covalently bounded to the wall. Changing, i.e.
D. Méhn, Z. Kónya, J. Halász, J.B. Nagy, B. Rác, A. Molnár, I. Kiricsi   +6 more
openaire   +2 more sources

MCM-41 deposition on alumina ceramic foams

Materials Letters, 2010
Alumina-based macro-porous ceramic foams were successfully coated with MCM-41 meso-porous materials using an in-situ one step hydrothermal synthesis. Low H2O/NaOH ratio in the starting mixture leads to a not uniform deposition of the meso-porous materials.
GRANATO T, LE PIANE F, TESTA, Flaviano, KATOVIC, Andrea, AIELLO R.   +4 more
openaire   +3 more sources

Catalytic Epoxidation of Cyclohexane on MCM-41 and Ti-MCM-41

2003
Mesoporous type MCM-41 and Ti-MCM-41 have been prepared and characterised by XRD, surface area and porosity evaluation and TEM. The solids were essayed as catalysts for the epoxidation of cyclohexane at two different temperatures. Only the samples containing Ti were active in the reaction being the most active the sample that was silylated.
G. Pecchi, P. Reyes, G. Borda, M. Oportus   +3 more
openaire   +1 more source

Cyclooctene epoxidation using Nb-MCM-41 and Ti-MCM-41 synthesized at room temperature

Applied Catalysis A: General, 2004
Abstract An efficient and simple method for preparing titanium or niobium containing MCM-41 has been developed. The mesoporous materials were synthesized at room temperature using tetraethoxysilane (TEOS), cetyltrimethylammonium bromide (CTMABr) as template and (NH 4 ) 2 TiF 6 or NH 4 [NbO(C 2 O 4 ) 2 (H 2 O) 2 ]·(H 2 O) 3 as metal source.
Jean Marcel R Gallo, Icaro S Paulino, Ulf Schuchardt   +2 more
openaire   +2 more sources

The photoluminescence of coumarin derivative encapsulated in MCM-41 and Ti-MCM-41

Dyes and Pigments, 2005
Coumarin derivative encapsulated in various mesoporous sieves was prepared by impregnation method. The effects of pore size and Ti-containing amounts on the fluorescence properties were investigated. High dispersion of the dye molecules could be realized on the composite of mesoporous sieves, and the electron transfer from the excited dye molecule to ...
Wenjuan Zhao, Dongmei Li, Bin He, Jinlong Zhang, Jiazhen Huang, Lizhong Zhang   +5 more
openaire   +1 more source

Cu–H-MCM-41, H-MCM-41 and Na-MCM-41 Mesoporous Molecular Sieve Catalysts for Isomerization of 1-Butene to Isobutene

Catalysis Letters, 2002
Cu–H-MCM-41, H-MCM-41 and Na-MCM-41 mesoporous molecular sieve catalysts were synthesized, characterized and investigated in the isomerization of 1-butene to isobutene. Introduction of copper in MCM-41 was found to play a positive role in enhancing the conversion of 1-butene and yield of isobutene and Cu–H-MCM-41 exhibited higher conversion of 1-butene
Narendra Kumar, Ville Nieminen, Lars Eric Lindfors, Tapio Salmi, Dmitry Yu. Murzin, Ensio Laine, Teemu Heikkilä   +6 more
openaire   +1 more source