نتایج جستجو برای: catalyst selectivity

تعداد نتایج: 86617  

2015
Marzia Galli James E M Lewis Stephen M Goldup

A rotaxane-based Au catalyst was developed and the effect of the mechanical bond on its behavior was studied. Unlike the non-interlocked thread, the rotaxane requires a catalytically innocent cofactor, the identity of which significantly influences both the yield and diastereoselectivity of the reaction. Under optimized conditions, Au(I) (the catalyst), Ag(I) (to abstract the Cl(-) ligand), and...

2007
T. A. Kainulainen M. K. Niemela

The activity, selectivity and stability of RhrC catalysts prepared from nitrate precursor on three different active carbon supports was determined in ethene hydroformylation. The different active carbon supports yielded catalysts, which had Ž . Ž . different extents of reduction 62–94% and dispersion 4–27% after hydrogen reduction. The best activity and selectivity Ž . in the formation of propa...

Journal: :Nature chemistry 2016
Johnny Saavedra Todd Whittaker Zhifeng Chen Christopher J Pursell Robert M Rioux Bert D Chandler

Industrial hydrogen production through methane steam reforming exceeds 50 million tons annually and accounts for 2-5% of global energy consumption. The hydrogen product, even after processing by the water-gas shift, still typically contains ∼1% CO, which must be removed for many applications. Methanation (CO + 3H2 → CH4 + H2O) is an effective solution to this problem, but consumes 5-15% of the ...

2012
A. Gharibi Kharaji A. Shariati

One of the main reactions that can be used to reduce greenhouse gases emissions is Reverse Water Gas Shift (RWGS) reaction. Through this reaction CO2 is converted to CO to produce beneficial chemicals such as methanol. In this paper Mo/Al2O3 catalyst was prepared and then promoted with Ni ions through impregnation method to produce Ni-Mo/Al2O3 catalyst. The structures of the catalysts were stud...

Journal: :nanochemistry research 0
fariborz mansouri chemistry department, tarbiat modares university, tehran, iran mehdi sheykhan chemistry department, guilan university, rasht, iran akbar heydari chemistry department, tarbiat modares university, tehran, iran

a mild, green and highly efficient route for regio-selective amination of oxiranes was developed via incorporation of mn(ii), fe(ii), co(ii), ni(ii), cu(ii) and zn(ii) cations onto the surface of hydroxyapatite-encapsulated γ-fe2o3 nanoparticles (γ-fe2o3@hap). among six magnetically recoverable catalytic systems denoted as [γ-fe2o3@hap-mii], the catalyst in which m designated as fe(ii) showed t...

Journal: :Angewandte Chemie 2012
Jan Prinz Roberto Gaspari Carlo A Pignedoli Jochen Vogt Peter Gille Marc Armbrüster Harald Brune Oliver Gröning Daniele Passerone Roland Widmer

Catalytic reactions are of highest technological and economic importance, especially in the field of chemical synthesis and exhaust gas treatment. About 80% of the reactions in chemical industry rely on catalysts, thus giving motivation for research in this area. There has been enormous progress in heterogeneous catalysis through the understanding of reaction mechanisms and the relation of cata...

Journal: :Nature chemistry 2012
Christian P Canlas Junling Lu Natalie A Ray Nicolas A Grosso-Giordano Sungsik Lee Jeffrey W Elam Randall E Winans Richard P Van Duyne Peter C Stair Justin M Notestein

New porous materials such as zeolites, metal-organic frameworks and mesostructured oxides are of immense practical utility for gas storage, separations and heterogeneous catalysis. Their extended pore structures enable selective uptake of molecules or can modify the product selectivity (regioselectivity or enantioselectivity) of catalyst sites contained within. However, diffusion within pores c...

Journal: :iranian journal of science and technology (sciences) 2015
m. karimkoshteh

the selective reduction of oximes with sodium borohydride (nabh4) in the presence of nano cu and charcoal was investigated. cu nanoparticles are widely used as catalysts; efficacious catalyst: copper and copper alloy nanometer feature high efficacy and selectivity, and can be used as catalyst in some reactions. we have shown that nabh4 in the presence of charcoal is an efficient protocol for th...

Using surface analysis, simultaneous effects of temperature (260-380ºC) and ethanol concentration (0-1%) on dimethyl ether (DME) selectivity, yields of hydrocarbon and DME, and methanol conversion were investigated in methanol dehydration reaction over γ-Al2O3 catalyst. Methanol conversion and yield of hydrocarbon/DME were found to be significantly affected by temperature and the temperature-et...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید