نتایج جستجو برای: hydrogenation

تعداد نتایج: 8711  

Journal: :Physical chemistry chemical physics : PCCP 2016
Daniel R Jones Sarwat Iqbal Simon A Kondrat Giacomo M Lari Peter J Miedziak David J Morgan Stewart F Parker Graham J Hutchings

A series of ruthenium catalysts supported on two different carbons were tested for the hydrogenation of lactic acid to 1,2-propanediol and butanone to 2-butanol. The properties of the carbon supports were investigated by inelastic neutron scattering and correlated with the properties of the ruthenium deposited onto the carbons by wet impregnation or sol-immobilisation. It was noted that the rat...

Journal: :Macromolecular rapid communications 2011
Justyna Trzaskowski Dorothee Quinzler Christian Bährle Stefan Mecking

Self-metathesis of undecenoic acid with [(PCy3)2Cl2Ru=CHPh] (2), followed by exhaustive hydrogenation yielded pure 1,20-eicosanedioic acid (5) (>99%) free of side-products from isomerization. Polycondensation with eicosane-1,20-diol (6), formed by reduction of the diol, yielded polyester 20,20 (Tm = 108 °C). By comparison, the known ADMET polymerization of undec-10-enyl undec-10-enoate (7), and...

Journal: :Angewandte Chemie 2010
Dianjun Chen Yutian Wang Jürgen Klankermayer

The development of transition-metal-catalyzed asymmetric hydrogenation could be stated as the cradle of modern enantioselective catalysis. Since the early asymmetric hydrogenation example from Knowles and Sabacky in 1968, the method has rapidly advanced over the years into an important tool in academia and chemical industry. In general, for these transformations the development of effective tra...

Journal: :Chemphyschem : a European journal of chemical physics and physical chemistry 2010
Wiebke Ludwig Aditya Savara Swetlana Schauermann Hans-Joachim Freund

Hydrogenation of unsaturated hydrocarbon compounds catalyzed by transition metals is traditionally believed to be a structure-insensitive reaction. However, recent progress in understanding the microscopic details of this process challenges the universality of this common belief. Recently, several examples of catalytic systems were described in the literature where hydrogenation of the olefinic...

Journal: :Physical review letters 2015
Jinglan Qiu Huixia Fu Yang Xu A I Oreshkin Tingna Shao Hui Li Sheng Meng Lan Chen Kehui Wu

The hydrogenation of monatomic silicene sheet on Ag(111) was studied by scanning tunneling microscopy and density functional theory calculations. It was observed that hydrogenation of silicene at room temperature results in a perfectly ordered γ-(3×3) superstructure. A theoretical model, which involves seven H atoms and rearranged buckling of Si atoms, was proposed and agrees with experiments v...

2014
Prathap Kumar

Soybean lecithin containing a mixture of phospholipids (PLs) is an important co product obtained during soybean oil refining. Saturated rich PLs find several applications in food, cosmetic and pharmaceutical areas. The present study reports a simple, rapid, efficient and continuous hydrogenation process using 10% Pd/C catalyst at various temperatures and pressures. Degree of hydrogenation was m...

2017
Wei Chen Robert Pestman Bart Zijlstra Ivo A. W. Filot Emiel J. M. Hensen

The mechanism of CO hydrogenation to CH4 at 260 °C on a cobalt catalyst is investigated using steady-state isotopic transient kinetic analysis (SSITKA) and backward and forward chemical transient kinetic analysis (CTKA). The dependence of CH x residence time is determined by 12CO/H2 → 13CO/H2 SSITKA as a function of the CO and H2 partial pressure and shows that the CH4 formation rate is mainly ...

2008
A. R. Beltramone D. E. Resasco W. E. Alvarez T. V. Choudhary

Hydrogenation of six model feeds containing three-, two-, and one-ring aromatic compounds was investigated to gain insights into the aromatic hydrogenation reaction chemistry over a commercial NiMo catalyst under practical reaction conditions. The hydrogenation reactivity of the aromatic compounds followed the following order: phenanthrene ∼ two-ring aromatics . one-ring aromatic. Comparison wi...

Journal: :Molecules 2012
Ryuhei Ikeda Ryoichi Kuwano

A variety of 3-substituted benzisoxazoles were reduced with hydrogen using the chiral ruthenium catalyst, {RuCl(p-cymene)[(R,R)-(S,S)-PhTRAP]}Cl. The ruthenium-catalyzed hydrogenation proceeded in high yield in the presence of an acylating agent, affording α-substituted o-hydroxybenzylamines with up to 57% ee. In the catalytic transformation, the N-O bond of the benzisoxazole substrate is reduc...

Journal: :Nano letters 2009
Hongjun Xiang Erjun Kan Su-Huai Wei Myung-Hwan Whangbo Jinlong Yang

It is highly desirable to produce narrow-width graphene nanoribbons (GNRs) with smooth edges in large scale. In an attempt to solve this difficult problem, we examined the hydrogenation of GNRs on the basis of first principles density functional calculations. Our study shows that narrow GNRs can be readily obtained from wide GNRs by partial hydrogenation. The hydrogenation of GNRs starts from t...

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