نتایج جستجو برای: catalyst

تعداد نتایج: 44027  

Journal: :Chemical communications 2010
Gang Wu Mark A Nelson Nathan H Mack Shuguo Ma Praveen Sekhar Fernando H Garzon Piotr Zelenay

A new non-precious metal oxygen reduction catalyst was developed via heat treatment of in situ polymerized polyaniline onto TiO(2) particles in the presence of Fe species. The TiO(2) provides for improved performance relative to a carbon black-based catalyst and, at a high catalyst loading, allows for reducing the performance gap between non-precious-metal catalyst and Pt/C to ca. 20 mV in RDE ...

2005
Carlo Resini Maria Concepción Herrera Delgado Laura Arrighi Luis J. Alemany Rinaldo Marazza Guido Busca

Experiments of propane and propene steam reforming have been performed over a Pd–Cu/c-Al2O3 catalyst and over a Ni/NiAl2O4 catalyst. Over the palladium-based catalyst, the steam reforming of propene is faster and more selective than steam reforming of propane. Over the Pd catalyst, the steam reforming of propane is likely inhibited by site poisoning. In contrast, over Ni-based catalyst the refo...

2014
Jinchong Zhao Lulu Zhang Nannan She Yunqi Liu Yongming Chai Chenguang Liu

A compound catalyst (RA) consisted of Ni, ZnO and HZSM-5 with functions of reactive adsorption desulfurization (RADS) and olefin aromatization for fluid catalytic cracking (FCC) gasoline upgrading was prepared. X-ray powder diffraction (XRD), temperature-programmed reduction and low-temperature N2 adsorption were used to characterize the properties of the catalysts. Performance evaluation by FC...

2004
Giovanni Fiengo Jessy W. Grizzle Jeffrey A. Cook

This paper describes active control of an aftertreatment system for a spark ignition engine equipped with a three-way catalyst and preand post-catalyst oxygen sensors. The control objective is to maximize the simultaneous conversion efficiencies of oxides of nitrogen and unburned hydrocarbons. Linear exhaust gas oxygen sensors are used to measure preand post-catalyst air-fuel ratio. A series co...

Journal: :iranian journal of catalysis 2011
arash shokrolahi abbas zali hamid reza pouretedal

the esterification of free fatty acids (ffa) with methanol is studied using sulfonated porous carbon (spc) as catalyst. in compare to the amorphous sugar catalyst and protonated nafion, the proposed catalyst shows stability and high efficient performance in biodiesel production. the highest initial rate of oleic acid conversion is obtained at catalyst loading of 1 mmol h+ and mole ratio of meoh...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 1996
fereydoon milani nejad siranoush sharzad a. bagher zadeh

oxidation of ethylene to ethylene oxide over silver catalyst and selenium modified catalyst has been studied by continuous flow and pulse techniques over the temperature range of 230-280 °c. the results are discussed in terms of reaction mechanisms proposed by others, rejecting mechanisms which involve peroxide formation. it has been shown that not only selectivity towards ethylene oxide produc...

Journal: :physical chemistry research 2014
ali akbar mirzaei maryam arsalanfar hamid reza bozorgzadeh abdoreza samimi

fischer-tropsch synthesis is a promising route for production of light olefins via co hydrogenation over transition metals. co is one of the most active metals for fischer-tropsch synthesis. some different variables such as preparation parameters and operational factors can strongly affect the selectivity of fischer-tropsch synthesis toward the special products. in the case of preparation varia...

Journal: :journal of nanostructures 2015
f. shahi m. akbarzadeh pasha a. a. hosseini z. s. arabshahi

nanometric carbid silicon (sic) supported monometallic and bimetallic catalysts containing fe, co, ni transition metals were prepared by wet impregnation method. multiwall carbon nanotubes (mwcnts) were synthesized over the prepared catalysts from catalytic decomposition of acetylene at 850°c by thermal chemical vapor deposition (tcvd) technique. the synthesized nanomaterials (catalysts and cnt...

Journal: :Chemical science 2017
Paul J Smith Simon A Kondrat Philip A Chater Benjamin R Yeo Greg M Shaw Li Lu Jonathan K Bartley Stuart H Taylor Michael S Spencer Christopher J Kiely Gordon J Kelly Colin W Park Graham J Hutchings

Zincian georgeite, an amorphous copper-zinc hydroxycarbonate, has been prepared by co-precipitation using acetate salts and ammonium carbonate. Incorporation of zinc into the georgeite phase and mild ageing conditions inhibits crystallisation into zincian malachite or aurichalcite. This zincian georgeite precursor was used to prepare a Cu/ZnO catalyst, which exhibits a superior performance to a...

2015
Jing Liu Jiandu Lei Jing He Lihong Deng Luying Wang Kai Fan Long Rong

The non-sulfided Ni-PTA/Al2O3 catalyst was developed to produce green diesel from the hydroprocessing of Jatropha oil. The Ni-PTA/Al2O3 catalyst was prepared by one-pot synthesis of Ni/Al2O3 with the co-precipitation method and then impregnanting Ni/Al2O3 with PTA solution. The catalysts were characterized with BET, SEM-EDX, TEM, XRD, XPS, TGA and NH3-TPD. The Ni and W species of the Ni-PTA/Al2...

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