MCM-41/ansa-zirconocene supported catalysts: Preparation, characterization and catalytic behaviour in ethylene polymerization

2009 ◽  
Vol 304 (1-2) ◽  
pp. 107-116 ◽  
Author(s):  
Carlos Alonso-Moreno ◽  
Damián Pérez-Quintanilla ◽  
Dorian Polo-Cerón ◽  
Sanjiv Prashar ◽  
Isabel Sierra ◽  
...  
Keyword(s):  
Ethylene Polymerization ◽  
Supported Catalysts ◽  
Catalysts Preparation ◽  
Catalytic Behaviour ◽  
Mcm 41

scholarly journals Nickel Phosphide Catalysts as Efficient Systems for CO2 Upgrading via Dry Reforming of Methane

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 446
Author(s):  
Miriam González-Castaño ◽  
Estelle le Saché ◽  
Cameron Berry ◽  
Laura Pastor-Pérez ◽  
Harvey Arellano-García ◽  
...  
Keyword(s):  
Supported Catalysts ◽  
Lower Surface ◽  
Catalytic Performance ◽  
Dry Reforming Of Methane ◽  
Oxidation Reactions ◽  
Surface Areas ◽  
Ceo2 Sample ◽  
Conversion Rates ◽  
Ni Oxidation ◽  
Catalytic Behaviour

This work establishes the primordial role played by the support’s nature when aimed at the constitution of Ni2P active phases for supported catalysts. Thus, carbon dioxide reforming of methane was studied over three novel Ni2P catalysts supported on Al2O3, CeO2 and SiO2-Al2O3 oxides. The catalytic performance, shown by the catalysts’ series, decreased according to the sequence: Ni2P/Al2O3 > Ni2P/CeO2 > Ni2P/SiO2-Al2O3. The depleted CO2 conversion rates discerned for the Ni2P/SiO2-Al2O3 sample were associated to the high sintering rates, large amounts of coke deposits and lower fractions of Ni2P constituted in the catalyst surface. The strong deactivation issues found for the Ni2P/CeO2 catalyst, which also exhibited small amounts of Ni2P species, were majorly associated to Ni oxidation issues. Along with lower surface areas, oxidation reactions might also affect the catalytic behaviour exhibited by the Ni2P/CeO2 sample. With the highest conversion rate and optimal stabilities, the excellent performance depicted by the Ni2P/Al2O3 catalyst was mostly related to the noticeable larger fractions of Ni2P species established.

Ethylene polymerization over supported catalysts [2,6-bis(imino)pyridyl iron dichloride/magnesium dichloride] with AlR3 as an activator

2005 ◽  
Vol 43 (10) ◽  
pp. 2128-2133 ◽  
Author(s):  
Tatiana B. Mikenas ◽  
Vladimir A. Zakharov ◽  
Lyudmila G. Echevskaya ◽  
Michail A. Matsko
Keyword(s):  
Ethylene Polymerization ◽  
Supported Catalysts

Technological Aspects of Ethanol Steam Reforming Processors for Molten Carbonate Fuel Cells

2006 ◽  
Author(s):  
S. Freni ◽  
F. Frusteri ◽  
N. Mondello ◽  
V. Chiodo ◽  
S. Siracusano ◽  
...  
Keyword(s):  
Steam Reforming ◽  
Supported Catalysts ◽  
Catalyst Activity ◽  
Supported Catalyst ◽  
Molten Carbonate Fuel Cell ◽  
Water Mixture ◽  
Molten Carbonate ◽  
Carbon Formation ◽  
Molten Carbonate Fuel Cells ◽  
Catalytic Behaviour

Bioethanol, obtained by biomass fermentation, could be an important hydrogen supplier as a renewable source. The availability of active, selective and stable catalyst for bioethanol steam reforming is a key point for the development of processes suitable to this purpose. In this work, the performance of different supported catalysts in the steam reforming of bioethanol at molten carbonate fuel cell (MCFC) operative condition has been focused and a decreasing activity has been related to the formation of carbon. Furthermore catalytic behaviour of a Ni supported catalyst has been tested under reforming condition both distillation industry’s waste and ethanol-water mixture. Results revealed that, superior alcohols (fusel oil) arising from the distillation process influence carbon formation and the presence of oxygen (ATR condition) preserves the catalyst activity which otherwise significantly deactivate mainly due to the carbon formation.

scholarly journals Production of value-added chemicals from esterification of waste glycerol over MCM-41 supported catalysts

2019 ◽  
Vol 8 (1) ◽  
pp. 128-134 ◽  
Author(s):  
Emine Kaya Ekinci ◽  
Nuray Oktar
Keyword(s):  
Acetic Acid ◽  
High Selectivity ◽  
Supported Catalysts ◽  
Value Added ◽  
Mass Spectrometry Analysis ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Glycerol Conversion ◽  
Spectrometry Analysis ◽  
Mcm 41

Abstract A series of active and selective MCM-41 supported catalysts have been successfully prepared and used for bioderived glycerol esterification with acetic acid to produce fuel additives. In the synthesis of MCM-41, an acidic hydrothermal synthesis route was used, and silicotungstic acid (STA) and zirconia (ZrO2) were added to the catalyst structure by wet impregnation. X-ray diffraction, nitrogen adsorption-desorption methods, scanning electron microscopy with energy-dispersive spectroscopy, and inductively coupled plasma-mass spectrometry analysis were used for characterizations of the catalysts. Diffuse reflectance infrared Fourier transform spectroscopy analyses of pyridine-adsorbed catalysts owns Lewis and Brønsted acidity hosting in one, which promotes the esterification reaction of glycerol into glycerol esters with high selectivity. Esterification of glycerol reactions were performed at temperature intervals of 105°C–200°C, with an amount of catalyst equal to 0.5 g, and glycerol/acetic acid molar ratio of 1:6 in a stirred autoclave reactor operated batchwise. STA and ZrO2-impregnated MCM-41 catalysts showed better performance with a complete glycerol conversion and high selectivity to triacetin.

Studies of supported catalysts for ethylene polymerization, prepared using organovanadium compounds

1989 ◽  
Vol 40 (2) ◽  
pp. 375-380
Author(s):  
S. A. Vasnetsov ◽  
V. A. Poluboyarov ◽  
V. A. Zakharov ◽  
G. A. Nesterov ◽  
L. I. Vyshinskaya ◽  
...  
Keyword(s):  
Ethylene Polymerization ◽  
Supported Catalysts

Hydrodesulfurization of Dibenzothiophene over Siliceous MCM-41-Supported Catalysts

2001 ◽  
Vol 199 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Anjie Wang ◽  
Yao Wang ◽  
Toshiaki Kabe ◽  
Yongying Chen ◽  
Atsushi Ishihara ◽  
...  
Keyword(s):  
Supported Catalysts ◽  
Mcm 41

Synthesis and Catalytic Applications of Novel Mesoporous Aluminosilicate Molecular Sieves

1996 ◽  
Vol 454 ◽  
Author(s):  
Kondam Madhusudan Reddy ◽  
Chunshan Song
Keyword(s):  
Molecular Sieves ◽  
Supported Catalysts ◽  
Metal Sulfide ◽  
Sodium Aluminate ◽  
Mesoporous Molecular Sieve ◽  
Mesoporous Molecular Sieves ◽  
Hydrogenation Catalysts ◽  
Mesoporous Aluminosilicate ◽  
Catalytic Applications ◽  
Mcm 41

ABSTRACTThis paper reports on the synthesis of four series of mesoporous aluminosilicate molecular sieves (Al-MCM-41) and their catalytic applications. Four different aluminum compounds were examined as Al source in the hydrothermal synthesis of the mesoporous aluminosilicates of MCM-41 type, including pseudo boehmite (alumina), aluminum sulfate, aluminum isopropoxide, and sodium aluminate. Each Al source was examined at three different feed Si/Al ratios in the synthesis. XRD results show that there are differences in the dioo-spacings for the samples prepared with different Al sources: sodium aluminate > Al isopropoxide > Al sulfate > pseudo boehmite. Such differences reveal that Al incorporation in the framework increases in the following order: pseudo boehmite < Al sulfate < Al isopropoxide < sodium aluminate. XRD also indicates that the synthesized Al-MCM-41 samples have different crystallinity. 27Al NMR and 29Si NMR reveal that most of the Al species in the samples prepared with pseudo boehmite were present in octahedral coordination, whereas in other samples nearly all the Al species are tetrahedral (in the framework). The acid characteristics of the synthesized molecular sieves were characterized by temperature-programmed desorption of n-butylamine, and by using 1,3,5-triisopropylbenzene hydrocracking as probe reaction. The results of TPD and probe reaction clearly indicate that the Al source used for synthesis has a major impact on the acidic and catalytic properties of Al-MCM-41. The samples prepared with Al isopropoxide and sodium aluminate are better as catalysts than those with Al sulfate and pseudo boehmite. We also explored the potential of mesoporous molecular sieves as support for noble metal hydrogenation catalysts and metal sulfide-based hydrotreating catalysts. Pd and Pt-loaded mesoporous molecular sieves were prepared and applied for hydrogenation of naphthalene and phenanthrene. The results show that mesoporous molecular sieve-supported catalysts are much more active than alumina- and titania-supported catalysts. The data for dibenzothiophene hydrodesulfurization suggest that Al-MCM-41 supported Co-Mo may be effective for deep desulfurization of distillate fuels.

scholarly journals Enhancing the activity of gold supported catalysts by oxide coating: towards efficient oxidations.

2021 ◽  
Author(s):  
Camila Palombo Ferraz ◽  
Sara Navarro-Jaén ◽  
Liane Marcia Rossi ◽  
Franck Yves Dumeignil ◽  
Mohamed Nawfal Ghazzal ◽  
...  
Keyword(s):  
Supported Catalysts ◽  
Oxide Coating ◽  
Core Shell ◽  
Furoic Acid ◽  
Catalytic Behaviour ◽  
Free Oxidation ◽  
Catalytic Performances

Core-shell SiO2@Au@TiO2 materials have shown excellent catalytic performances in the base-free oxidation of furfural (FF) to furoic acid (FA). The enhanced catalytic behaviour with respect to that observed over supported...

Sign in / Sign up

Export Citation Format

Share Document