نتایج جستجو برای: catalyst selectivity

تعداد نتایج: 86617  

Journal: :iranian chemical communication 2014
sobhan rezayati zahra erfani saman rezayati rahimeh hajinasiri marzieh rekavandi

1,1-diacetates(acylals) were prepared by direct condensation of various aldehydes with acetic anhydride using dipyridine cobalt chloride (copy2cl2) as an efficient and green catalyst under solvent-free conditions at room temperature. the important features of this catalyst method are that the catalyst is solid, stable at high temperatures, soluble in water, stable in air, immiscible in common o...

Journal: :iranian journal of catalysis 2014
kasim mohammed hello hayder mihsen mosa mosa

2,4-dinitrophenylhydrazanomethylphenol (dnphmp) was immobilized onto silicate rice husk ash to form a heterogeneous catalyst denoted as rhdnph. the elemental and edx analysis of rhdnph showed the nitrogen is incorporated into silica. the rhdnph had 154.6 m2g-1 as a specific surface area. the ft-ir clearly showed the appearance of –nh and c=n absorption band at the expected range. the tga curve ...

2011
Sardar Ali Noor Asmawati Mohd Zabidi Duvvuri Subbarao

This paper presents the synthesis and characterization of monometallic and bimetallic cobalt and iron nanoparticles supported on alumina. The catalysts were prepared by a wet impregnation method. Samples were characterized using temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO), CO-chemisorption, transmission electron microscopy (TEM), field emission scanning electr...

2008
P R Elowe C Mccann P G Pringle S K Spitzmesser J E Bercaw

A series of bis(diphenylphosphino)amine ligands with a donor group attached to the nitrogen linker have been prepared. Metalation of these ligands with chromium trichloride provides precursors to highly active, relatively stable, and selective catalysts for trimerization and tetramerization of ethylene. It has been demonstrated in oligomerization reactions performed at 1 and 4 atm of ethylene t...

2003
Enrique Iglesia

Catalyst productivity and selectivity to C5+ hydrocarbons are critical design criteria in the choice of Fischer-Tropsch synthesis (FTS) catalysts and reactors. Cobalt-based catalysts appear to provide the best compromise between performance and cost for the synthesis of hydrocarbons from CO/H2 mixtures. Optimum catalysts with high cobalt concentration and site density can be prepared by control...

2015
Luis Lopez Jorge Velasco Alberto Marinas Saul Cabrera Magali Boutonnet

The thermochemical processing of biomass is an alternative route for the manufacture of fuel-grade ethanol, in which the catalytic conversion of syngas to ethanol is a key step. The search for novel catalyst formulations, active sites and types of support is of current interest. In this work, the catalytic performance of an Rh/MCM-41 catalyst has been evaluated and compared with a typical Rh/Si...

2017
Bertrand Reuillard Khoa H Ly Timothy E Rosser Moritz F Kuehnel Ingo Zebger Erwin Reisner

The development of high-performance electrocatalytic systems for the controlled reduction of CO2 to value-added chemicals is a key goal in emerging renewable energy technologies. The lack of selective and scalable catalysts in aqueous solution currently hampers the implementation of such a process. Here, the assembly of a [MnBr(2,2'-bipyridine)(CO)3] complex anchored to a carbon nanotube electr...

2005
Carlo Resini Maria Concepción Herrera Delgado Laura Arrighi Luis J. Alemany Rinaldo Marazza Guido Busca

Experiments of propane and propene steam reforming have been performed over a Pd–Cu/c-Al2O3 catalyst and over a Ni/NiAl2O4 catalyst. Over the palladium-based catalyst, the steam reforming of propene is faster and more selective than steam reforming of propane. Over the Pd catalyst, the steam reforming of propane is likely inhibited by site poisoning. In contrast, over Ni-based catalyst the refo...

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