نتایج جستجو برای: cobalt based catalyst

تعداد نتایج: 2994791  

Journal: :Nanoscale 2014
Yun-Pei Zhu Tie-Zhen Ren Zhong-Yong Yuan

Organic-inorganic hybrid of cobalt phosphonate hollow nanostructured spheres were prepared in a water-ethanol system through a mild hydrothermal process in the absence of any templates using diethylenetriamine penta(methylene phosphonic acid) as bridging molecule. SEM, TEM and N2 sorption characterization confirmed a hollow spherical micromorphology with well-defined porosity. The structure and...

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...

Journal: Journal of Nanoanalysis 2014

Functionalization of carbon nanotube (CNT) was performed, during preparation of Fischer–Tropsch synthesis (FTS) via cobalt nanocatalysts, to modify the surface properties of CNT support. Common and functionalized CNT supported cobalt nanocatalysts were prepared using impregnation wetness method with cobalt loading of 15 wt.%. The catalysts were characterized by Brunauer–Emmett–Teller (BET), Fou...

Journal: :Organic & biomolecular chemistry 2011
Feng Yu Xi-Chang Zhang Fei-Fei Wu Ji-Ning Zhou Wenjun Fang Jing Wu Albert S C Chan

In the presence of PhSiH(3) as the hydride donor, catalytic amounts of non-racemic dipyridylphosphine and an easy-to-handle cobalt salt Co(OAc)(2)·4H(2)O formed in situ an effective catalyst system for the asymmetric reduction of a diverse range of aryl alkyl ketones with moderate-to-excellent enantioselectivities (up to 96% ee). This approach tolerated the handling of both catalyst and reactan...

2017
Xue Xu Yong Wang Xin Cui Lukasz Wojtas X. Peter Zhang

For the first time, a-formyldiazoacetates have been successfully applied for the asymmetric cyclopropanation of alkenes via Co(II)-based metalloradical catalysis. The cobalt(II) complex of the D2symmetric chiral amidoporphyrin [Co(3,5-DiBu-ChenPhyrin)] is an effective metalloradical catalyst that can activate a-formyldiazoacetates to cyclopropanate both aromatic and aliphatic olefins with varie...

2014
Martin Fouquet Bernhard C. Bayer Santiago Esconjauregui Christian Thomsen Stephan Hofmann John Robertson

We show that catalyst pre-treatment conditions can have a profound effect on the chiral distribution in single-walled carbon nanotubes chemical vapor deposition. Using a SiO2-supported Cobalt model catalyst and pre-treatment in NH3, we obtain a comparably narrowed chiral distribution with a downshifted tube diameter range, independent of the hydrocarbon source. Our findings demonstrate that the...

Journal: :Journal of the American Chemical Society 2015
Nikolay Kornienko Joaquin Resasco Nigel Becknell Chang-Ming Jiang Yi-Sheng Liu Kaiqi Nie Xuhui Sun Jinghua Guo Stephen R Leone Peidong Yang

The generation of chemical fuel in the form of molecular H2 via the electrolysis of water is regarded to be a promising approach to convert incident solar power into an energy storage medium. Highly efficient and cost-effective catalysts are required to make such an approach practical on a large scale. Recently, a number of amorphous hydrogen evolution reaction (HER) catalysts have emerged that...

Amir Hossein Haghighaty, Kambiz Larijani, Shahram Moradi Dehaghi

In this research, initially, the sol-gel method was employed to produce γ-alumina and TiO2 catalysts with core-shell structure. Iron (III) was used as a dopant. The newlyproduced core-shells were Fe/TiO2// Fe/ γ-Al2O3 (FTFA). Sulfonated cobalt phthalocyanine was used as a dye pollutant in Merox process. By doping Fe in TiO2 catalyst, the ef...

Journal: :Nature communications 2015
Cheng-Shiuan Li Gérôme Melaet Walter T Ralston Kwangjin An Christopher Brooks Yifan Ye Yi-Sheng Liu Junfa Zhu Jinghua Guo Selim Alayoglu Gabor A Somorjai

Carbon dioxide capture and use as a carbon feedstock presents both environmental and industrial benefits. Here we report the discovery of a hybrid oxide catalyst comprising manganese oxide nanoparticles supported on mesoporous spinel cobalt oxide, which catalyses the conversion of carbon dioxide to methanol at high yields. In addition, carbon-carbon bond formation is observed through the produc...

Journal: :Angewandte Chemie 2015
Juan J Velasco-Velez Verena Pfeifer Michael Hävecker Robert S Weatherup Rosa Arrigo Cheng-Hao Chuang Eugen Stotz Gisela Weinberg Miquel Salmeron Robert Schlögl Axel Knop-Gericke

Electrochemically grown cobalt on graphene exhibits exceptional performance as a catalyst for the oxygen evolution reaction (OER) and provides the possibility of controlling the morphology and the chemical properties during deposition. However, the detailed atomic structure of this hybrid material is not well understood. To elucidate the Co/graphene electronic structure, we have developed a flo...

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