Results 251 to 260 of about 37,643 (291)

Sorption on as-synthesized MCM-41

Journal of Thermal Analysis and Calorimetry, 2007
Mesoporous materials MCM-41 with the hexagonal arrangement of pores were obtained using dodecyltrimethylammonium bromide and octadecyltrimethylammonium bromide as templating surfactants. Adsorption of toluene and propan-1-ol on the as-synthesized MCM-41 silica samples was investigated using the TG-DTG, DTA and DSC techniques.
J. Goworek, A. Kierys, M. Iwan, W. Stefaniak   +3 more
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?????????????????????????? ???????????????????????? ???????????????????????????? ?????????????? ???? VO???/MCM-41 ?? VO???/Ti-MCM-41 ?? ???????????????????? ?????????????????? ?? ????????????????

2023
???????????????????? ?????????? ?????????????????? ???????????????????????? ?????????????????????????????? ?????????? ???????????? ?? ?????????????????? ???????????????????????????? ?????????????????????? ?????????? MCM-41 ???? ???????????????????????? ?????????????????? VO???-????????, ???? ????????????-?????????????? ???? ?????????????????????? ??????
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Preparation of Pt°/MCM-41: effect of drying on MCM-41 structure and Pt° dispersion

2006
1. Abstract Pt°/MCM-41 catalysts were prepared by electrostatic adsorption of Pt(NH3)42+ at pH=8, followed by calcination under O2 and reduction. This procedure allows to prepare highly dispersed Pt° nanoparticles (D>76%), but has the drawback to modify significantly the structure of the ordered mesoporous support during the washing-drying step ...
Zhu, Baichun, Letellier, Franck, Blanchard, Juliette, Fajerwerg, Katia, Louis, Catherine, Guillaume, Denis, Uzio, Denis, Breysse, Miehèle   +7 more
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Synthesis and characterization of Cu-MCM-41 and Ni-MCM-41 type catalytic materials

2020
oz Cu-MCM-41 VE Nİ-MCM-41 TİPİ KATALİTİK MALZEMELERİN SENTEZLENMESİ VE KARAKTERİZASYONU Nalbant, Aslı Yüksek Lisans, Kimya Mühendisliği Tez Yöneticisi: Prof. Dr. Timur DOĞU Ortak Tez Töneticisi: Prof. Dr. Suna BALCI Ocak 2005, 128 sayfa Mezo gözenekli malzemelerin 1992 yılında Mobil araştırmacıları tarafından sentezi katalitik uygulamalarında yeni ...
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Diffusion of guest molecules in MCM-41 agglomerates

The Journal of Chemical Physics, 2007
The pulsed field gradient nuclear magnetic resonance method has been used to study self-diffusion of cyclohexane in a commercial MCM-41 material at different external gas pressures from zero to saturated vapor pressure. It is found that the effective diffusivities exhibit three different regions with increasing pressure: decrease at low pressures, a ...
Rustem, Valiullin, Muslim, Dvoyashkin, Pavel, Kortunov, Cordula, Krause, Jörg, Kärger   +4 more
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Molecular Sieves (MCM-41, Al-MCM-41) Characterization Using Different Silica Sources

Materials Science Forum, 2012
Research, synthesis and catalytic application of molecular sieves areas has been constituting a large field of development and prominence in recent decades, due to the large potential of these materials in respect of theirs catalytic properties. The need for costs reduction in the production of these structures, has encouraged the search for new ...
José Otávio Peroba Nascimento Santos, Rafaela Pereira Roque de Miranda, Deivid Sousa Figueiroa, Carlos Eduardo Pereira, Bianca Viana de Sousa   +4 more
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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
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Acidity study of Nb-containing MCM-41 mesoporous materials. Comparison with that of Al-MCM-41

Catalysis Letters, 1997
The acidity of Nb-MCM-41 molecular sieves as well as their hydrogen forms was studied using FTIR spectroscopy with pyridine and 2,6-dimethylpyridine as probe molecules and in test reactions (isopropanol and cumene decomposition). The number of Lewis acid sites (LAS) and Bronsted acid sites (BAS) was estimated from the intensity of IR bands at 1450 and ...
M. Ziolek, I. Nowak, J.C. Lavalley
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STRUCTURAL PROPERTIES OF Cu-MCM-41 AND Cu-Al-MCM-41 (Si/Al=30) CATALYSTS

2002
Cu-MCM-41 and Cu-Al-MCM-41 samples have been obtained by ion exchange of the MCM-41 and Al-MCM-41 matrices prepared by hexadecyltrimethylammonium cloride, tetraethyl orthosilicate, aluminum isopropoxide and an ammonia solution. The aluminum concentration affects the MCM-41 textural properties and large amount of extra-framework aluminum species are ...
FERRARIS G., MORETTI, GIULIANO, FIERRO G., LOJACONO, Mariano   +3 more
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Synthesis and characterization of bimetallic Ga,Al-MCM-41 and Fe,Al-MCM-41

2002
The structural and acidic properties of bimetallic Fe,Al-MCM-41 and Ga,Al-MCM-41 were compared with the Al-MCM-41. The competitive presence of Al and Fe/Ga in the MCM-41 walls and the formation of extra-framework Al and Fe/Ga species induces changes in the nature of the acid sites and therefore of their catalytic properties.
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