نتایج جستجو برای: alkali catalyst

تعداد نتایج: 60055  

Journal: :iranian journal of science and technology (sciences) 2012
a. malekzadeh

oxidative coupling of methane has been studied over (mn+a+w)/sio2 catalysts in a continuous–flow microreactor, where a represents an alkali ion of li, na, k or cs having different weight percents. the main aim of this study is to find the role of alkali ions in interaction between mn and w species with sio2 to make a proper structure for catalyzing oxidative coupling of methane (ocm) reaction. ...

2005
X Y Tao G Van Tendeloo

A series of novel one-dimensional carbon nanomaterials have been synthesized on an alkali-element-modified Cu catalyst, via a simple chemical vapour deposition method. The alkali-element doping of the Cu catalyst plays a key role in the controllable synthesis of carbon nanomaterials, signifying a novel approach to modifying the Cu catalyst. Owing to their unique morphology and fine quality, the...

2003
R. J. Berger J. G. van Ommen

Natural gas may be used instead of hydrogen as fuel for the molten carbonate fuel cell (MCFC) by steam reforming the natural gas inside the MCFC, using a nickel catalyst (internal reforming). The severe conditions inside the MCFC, however, require that the catalyst has a very high stability. In order to find suitable types of nickel catalysts and to obtain more knowledge about the deactivation ...

2004
R. J. Berger G. van Ommen

A nickel catalyst to be used for internal steam reforming in a molten carbonate fuel cell (MCFC) must be resistant to the alkali components (Li and K species) of the electrolyte; these components can reach the catalyst from the anode by either transport via the vapor phase or by means of surface creep along the walls. In a series of experiments for determining the rates of transport, it was fou...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2013
farnaz tahriri zangeneh abbas taeb khodayar gholivand saeed sahebdelfar

the kinetics of catalyst deactivation and coke formation during dehydrogenation of propane over supported pt–based catalysts and, in particular, the effect of alkali metal promoters on catalyst activity and stability were studied. the analysis of propane conversion data showed that there is an optimum level of alkali metal promoter loading for both catalyst activity and stability.a model based ...

2015
Matthias Kusche Karen Bustillo Friederike Agel Peter Wasserscheid

Herein, we describe an economical and convenient method to improve the performance of Pt/alumina catalysts for the water-gas shift reaction through surface modification of the catalysts with alkali hydroxides according to the solid catalyst with ionic liquid layer approach. The results are in agreement with our findings reported earlier for methanol steam reforming. This report indicates that a...

2018
Roderigh Y. Rohling Evgeny Uslamin Bart Zijlstra Ionut C. Tranca Ivo A. W. Filot Emiel J. M. Hensen Evgeny A. Pidko

The one-pot Diels-Alder cycloaddition (DAC)/dehydration (D) tandem reaction between 2,5-dimethylfuran and ethylene is a potent pathway toward biomass-derived p-xylene. In this work, we present a cheap and active low-silica potassium-exchanged faujasite (KY, Si/Al = 2.6) catalyst. Catalyst optimization was guided by a computational study of the DAC/D reaction mechanism over different alkali-exch...

2008
Baoshan HU Kaoru Fujimoto

A b as well as methanol selectivity (~90%) were achieved with a mass space velocity of 2700 L/h.kg-cat. at 433 K and 5.0 MPa via ethyl formate in slurry phase. This study investigated the influences of co-precipitation PH value of copper magnesium catalyst, types of alkali compounds as carbonylation promoters and impregnation agents, alcohol solvent on the reaction performances. It was also fou...

2005
Yasuyuki Ishida Koichi Hata Koji Tanifuji Tatsuya Hasegawa Kuniyuki Kitagawa

The effects of various additives, such as an inorganic alkali and metal catalyst, on the hydrothermal process were examined to recover hydrogen from biomass with high efficiency and selectivity at relatively low temperatures around 400°C. At first, a cellulose sample as a model biomass was subjected to the hydrothermal process at 400°C under 25 MPa in the presence of an alkali, sodium carbonate...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2013
ya-feng li yong-peng yuan kai-kai wang jun jia xiao-lin qin

the conversion of the cellulose into 5-hmf would experience three steps, cellulose to glycose, glycose to fructose and fructose to 5-hmf. chloride ion can break down the hydrogen bond in cellucose, chromium can catalyze the isomerization of glycose to fructose, and the high temperature is helpful to cyclohydration of fructose to 5-hmf. in this paper, the sawdust has been directly degraded into ...

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