نتایج جستجو برای: acetylene hydrogenation

تعداد نتایج: 12112  

Journal: :international journal of nanoscience and nanotechnology 2010
m. masoumi m. r. mehrnia m. m. montazer-rahmati a. m. rashidi

chemical vapor deposition was employed to synthesize carbon nanotubes with ni-loaded mcm-41 and mcm-48 as catalysts and acetylene as precursor at 750°c. mesoporous ni mcm-41 and ni mcm-48 molecular sieves were synthesized by a hydrothermal method and were characterized by xrd and n2 adsorption isotherm. the catalytically synthesized carbon materials were characterized with raman spectroscopy, n...

ژورنال: :international journal of new chemistry 0

abstract: electrical sensitivity of a boron nitride nanotube (bnnt) was examined toward ethyl acetylene (c4h6) molecule by using density functional theory (dft) calculations at the b3lyp/6-31g (d) level, and it was found that the adsorption energy (ead) of ethyl acetylene the pristine nanotubes is about -1.60kcal/mol. but when nanotube has been doped with si and al atoms, the adsorption energy ...

2009
Yichen Tan

INTRODUCTION Asymmetric hydrogenation of unsaturated organic compounds has been established as one of the most efficient methods for the preparation of chiral, non-racemic substrates. Among hydrogenation of various substrates, the asymmetric hydrogenation of heteroarenes provides a straightforward approach to a wide range of enantiomerically pure saturated heterocycles, which are subunits of ma...

Journal: :Angewandte Chemie 2002
Ai-Guo Hu Yu Fu Jian-Hua Xie Hai Zhou Li-Xin Wang Qi-Lin Zhou

Optically active -arylalkylamines are an important class of compounds that are widely used in organic and pharmaceutical synthesis, and much effort has been made to develop efficient asymmetric synthetic methods for them.[1] Asymmetric catalytic hydrogenation of enamides, initiated by Kagan et al. ,[2] provides a direct and convenient route to chiral amine derivatives. However, many well-known ...

2008
Rong Xiang Erik Einarsson Jun Okawa Yuhei Miyauchi Shigeo Maruyama

Addition of only 1% of acetylene into ethanol was found to enhance the growth rate of singlewalled carbon nanotubes (SWNTs) by up to ten times. Since acetylene is a byproduct of the thermal decomposition of ethanol, this suggests an alternative fast reaction pathway to the formation of SWNTs from ethanol via byproducts of decomposition. This accelerated growth, however, only occurred in the pre...

Journal: :Chemical science 2017
Jiwen Jian Wei Li Xuan Wu Mingfei Zhou

The organo-boron species formed from the reactions of boron atoms with acetylene in solid neon are investigated using matrix isolation infrared spectroscopy with isotopic substitutions as well as quantum chemical calculations. Besides the previously reported single C-H bond activation species, a cyclic-HBC2BH diboron species is formed via double C-H bond activation of acetylene. It is character...

2017
Huoli Zhang Youchao Wang Yan Wang Jianliang Cao Peng Kang Qingjie Tang Mingjie Ma Cláudia Gomes Silva

Pd nanoparticles (PdNPs) stabilized by methyl cellulose (MC) were synthesized in an aqueous solution, which are monodispersed nanoparticles. PdNPs/α-Al2O3 catalyst was prepared with monodispersed PdNPs and showed better catalytic performance than Pd/α-Al2O3 catalyst prepared by the incipient wetness impregnation method using Pd(NO3)2 as a precursor. The catalysts were characterized by transmiss...

Journal: :Nanoscale 2015
Amr M Abdelkader Hollie V Patten Zheling Li Yiqiang Chen Ian A Kinloch

We demonstrate a facile and scalable electrochemical approach to exfoliate graphite, which permits in situ hydrogenation of the resultant graphene via a solvated NR(4+) graphite compound in quaternary ammonium-based deep eutectic solvents. Spectroscopic studies reveal the presence of sp(3) C-H bonds in the hydrogenated graphene. The resulting materials consist of micrometre-sized and predominan...

Journal: :Journal of breath research 2010
M Metsälä F M Schmidt M Skyttä O Vaittinen L Halonen

We have measured the acetylene concentration in the exhaled breath of 40 volunteers (31 non-smokers, nine smokers) using near-infrared cavity ring-down spectroscopy. The acetylene levels were found to be the same as in ambient air for non-smokers, whereas elevated levels were observed for smokers. Real-time measurements with sub-second time resolution have been applied to measure the eliminatio...

Journal: :The journal of physical chemistry. B 2005
J R Hahn W Ho

A variable-low-temperature scanning tunneling microscope (STM) was used to observe oxygen (O2), ethylene (C2H4), and acetylene (C2H2) molecules on a Ag(110) surface and the various complexes that were formed between these two hydrocarbons and oxygen at 13 K. Ethylene molecule(s) were moved to the vicinity of O2 either by STM tunneling electrons at 13 K or thermally at 45 K to form (C2H4)x-O2 (x...

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