نتایج جستجو برای: movtenbo catalyst

تعداد نتایج: 44029  

2005
H. Cui X. Yang L. R. Baylor D. H. Lowndes

Cone-shaped nanostructures of mixed composition (nanocones) and largely graphitic nanofibers were synthesized on silicon substrates using iron/platinum alloy nanoparticles as the catalyst in a direct-current plasma enhanced chemical vapor deposition reactor. The catalyst nanoparticles were monodisperse in size with an average diameter of 3 (±1) nm. The nanocones were produced on laterally widel...

2010
A Rehman M Kamil A K Gupta A K Bhatnagar

The present study deals with the selective hydrogenation of menthone to menthol in a Parr reactor. The reactions are carried out in the temperature range of 100-200°C, pressure range of 5-20 kg/cm, 100 mL solvent and catalyst to substrate ratio ranging from 0-10% for a reaction time of 4-5 h. The samples are then analyzed using a gas chromatograph for determining the conversion and then selecti...

Journal: :Journal of mass spectrometry : JMS 2010
Cornelius T Martha Willem-Jan van Zeist F Matthias Bickelhaupt Hubertus Irth Wilfried M A Niessen

Ferrocene is a popular template in material science due to its exceptional characteristics that offer the ability to optimize the selectivity and activity of catalysts by the addition of carefully selected substituents. In combinatorial catalyst development, the high susceptibility to electrophilic substitution reactions offers the opportunity for the rapid introduction of molecular diversity. ...

2013
Chengming Zhang Lequan Liu Xinjiang Cui Lirong Zheng Youquan Deng Feng Shi

The controllable preparation of nano-gold catalyst maintains a challenge. Except the parameters have been revealed before, here we'd like to show that controllable preparation of active nano-gold catalyst can be achieved using chlorine as an indicator. By tracing the chlorine concentration in the washing step, a series of Au/Fe2O3 catalysts were prepared with co-precipitation method. The applyi...

Journal: :Journal of the American Chemical Society 2007
David A Evans Keith R Fandrick Hyun-Ji Song Karl A Scheidt Risheng Xu

The enantioselective Friedel-Crafts addition of a variety of indoles catalyzed by bis(oxazolinyl)pyridine-scandium(III) triflate complexes (Sc(III)-pybox) was accomplished utilizing a series of beta-substituted alpha,beta-unsaturated phosphonates and alpha,beta-unsaturated 2-acyl imidazoles. The acyl phosphonate products were efficiently transformed into esters and amides, whereas the acyl imid...

Journal: :ACS nano 2010
Michael J Behr K Andre Mkhoyan Eray S Aydil

We examined the structure, morphology, and orientation of catalyst nanoparticles used for seeding and growing multiwall carbon nanotubes (MWCNTs) by plasma enhanced chemical vapor deposition in CH4/H2 gas mixtures. Iron catalyst nanocrystals are converted to Fe3C in CH4/H2 plasmas and the MWCNTs grow from Fe3C nanocrystals. Initially faceted and equiaxed catalyst nanocrystals are distorted and ...

2012
M. Soda A. Rudolph D. Schuh E. Reiger

We investigate the correlation between the Ga concentration of the catalyst droplet and the adopted crystal structure of individual GaAs nanowires grown by molecular-beam epitaxy using Au as a catalyst material. Through a postgrowth analysis the Ga content of the catalyst droplet during growth is estimated and related to the observed crystal structure of the nanowires. Depending on the Ga conce...

Journal: :Molecules 2011
Stojan Stavber

Selectfluor™ F-TEDA-BF4 (1-chloromethyl-4-fluoro-1,4-diazoniabicyclo [2.2.2]octane bis(tetrafluoroborate) is not only one of the most efficient and popular reagents for electrophilic fluorination, but as a strong oxidant is also a convenient mediator or catalyst of several "fluorine-free" functionalizations of organic compounds. Its applications as a mediator in transformations of oxidizable fu...

2007
Shinichi Itsuno Miyuki Takahashi Yukihiro Arakawa Naoki Haraguchi

Polymer-supported chiral 1,2-diamine derivatives have been prepared. The polymers containing free 1,2-diamine moiety were applied to enantioselective hydrogenation catalyst by combination with RuCl2-BINAP complex. Asymmetric hydrogenation of aromatic ketones was performed by means of the polymeric catalyst derived from these polymers to give the chiral secondary alcohols with high ee in quantit...

Journal: :Physical review letters 2011
Dmitri Schebarchov Shaun C Hendy Elif Ertekin Jeffrey C Grossman

We use molecular dynamics and simple thermodynamic arguments to model the interaction between catalyst nanoparticles and carbon nanotube caps, and we illustrate how the competition between cap strain energy and adhesion plays a role in the lifting of these caps from the catalyst surface prior to tube elongation. Given a particular cap structure, we show that there is a lower bound on the cataly...

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