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Catalysis and Reaction Engineering Commons™

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2000

Articles 1 - 21 of 21

Full-Text Articles in Catalysis and Reaction Engineering

Template Synthesis Of Nano-Structured Electrode Materials And Its Electrochemical Performance, Jian Zhao, Quan Yong Gao, Yong Yang, Zu-Geng Lin Nov 2000

Template Synthesis Of Nano-Structured Electrode Materials And Its Electrochemical Performance, Jian Zhao, Quan Yong Gao, Yong Yang, Zu-Geng Lin

Journal of Electrochemistry

In this letter, various nano structured materials such as spinel LiMn 2O 4 nanotubes/nanowires and carbon nanotubes have been prepared by using porous alumina template. The prepared template and materials have been characterized by AFM and TEM techniques. It is shown that size of the nanotubes can be conveniently controlled by using template method. Some preliminary results of cyclic voltammetry about nano structured LiMn 2O 4 are also reported.

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The Development Of Carbon Monoxide Tolerant Catalysts For Proton-Exchange Membrane Fuel Cell, Zhong Jun Hou, Hong Mei Yu, Bao Lian Yi, Ming Han Nov 2000

The Development Of Carbon Monoxide Tolerant Catalysts For Proton-Exchange Membrane Fuel Cell, Zhong Jun Hou, Hong Mei Yu, Bao Lian Yi, Ming Han

Journal of Electrochemistry

High over potential of proton exchange membrane fuel cell(PEMFC) anode caused by carbon monnoxide poisoning when reformate or methanol is used as fuel is main obstacle to the high performance of PEMFCs.Using carbon monoxide tolerant catalysts is the most hopeful way to solve the CO problem.The CO poisoning problem is reviewed briefly in this paper,and the development of CO tolerant catalysts is introduced in details, including electrocatalysts activity, preparation method and mechanism of tolerance to CO.Mo and W can improve catalysts' CO tolerance.Multi component catalysts are expected to be more tolerant to CO.

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Studies Of Adsorption And Oxidation Of Ethanol On Nm-Pt/Gc Electrode——I.Cyclic Voltammograms And In-Situ Ftir Spectroscopy In Alkaline Media, Guo-Lian Chen, Shi-Gang Sun, Sheng-Pei Chen, Zhi-You Zhou Nov 2000

Studies Of Adsorption And Oxidation Of Ethanol On Nm-Pt/Gc Electrode——I.Cyclic Voltammograms And In-Situ Ftir Spectroscopy In Alkaline Media, Guo-Lian Chen, Shi-Gang Sun, Sheng-Pei Chen, Zhi-You Zhou

Journal of Electrochemistry

The electro_oxidation of ethanol on nm_Pt/GC electrode in alkaline solutions containing 0.02 mol·L -1 NaOH+0.1 mol·L -1 CH 3CH 2OH was investigated by using cyclic voltammetry and in_situ FTIR spectroscopy. The experimental results demonstrated that the main product of ethanol oxidation is CH 3COO -,only very small amount of CH 3CHO has been determined simultaneously. In contrast with the dual path reaction mechanism for the oxidation of ethanol in acid media,the oxidation of ethanol in alkaline media didn't pass through the dissociative adsorption,and no adsorbed species could be determined even using a nm_Pt/GC electrode that gives rise to enhancement of …

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Investigation Of A Complex Lithium Cobalt Nickel Oxide As Lithium Ion Battery Cathode Materials Prepared By A New Citrate Sol-Gel Method, Jing-Li Han, Qing Guo Liu Nov 2000

Investigation Of A Complex Lithium Cobalt Nickel Oxide As Lithium Ion Battery Cathode Materials Prepared By A New Citrate Sol-Gel Method, Jing-Li Han, Qing Guo Liu

Journal of Electrochemistry

The synthesis and electrochemical characteristics of lithium cobalt nickel oxide as cathode materials for rechargeable lithium batteries were investigated. It was clarified from these investigations that lithium cobalt nickel oxide has been produced from basic cobalt carbonate,basic nickel carbonate, lithium carbonate, and citrate. LiNi 0.8 Co 0.2 O 2 prepared under the stream of oxygen gas showed a higher cycling capacity of (～190 mAhg 1 ).

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A New Method For The Preparation Of The Electrodes With Very Low Platinum Loading Used In Proton Exchange Membrane Fuel Cell, Zhi-Gang Shao, Bao-Lian Yi, Ming Qiao Ya-Guang Han, Hao Liu, Jing-Rong Yu Aug 2000

A New Method For The Preparation Of The Electrodes With Very Low Platinum Loading Used In Proton Exchange Membrane Fuel Cell, Zhi-Gang Shao, Bao-Lian Yi, Ming Qiao Ya-Guang Han, Hao Liu, Jing-Rong Yu

Journal of Electrochemistry

Research and development on low platinum loading electrode is very important in reducing the cost of proton exchange membrane fuel cell(PEMFC)stack.This paper has put forward a new method to prepare the electrode of PEMFC. The pore forming substances were used in this methd. The low platinum loading electrodes (0.02 mgPtcm -2 )have already been prepared with the method. Compared with the traditional method, the new method is simple, cheep, and easy to scale up. The superior composition of the electrodes is catalyst: pore forming substance: Nafion= 331. The performance of a single cell using this kind of electrodes and Nafion …

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Cathodic Indirect Oxidation Of Organic Compounds(Ⅱ)——Cathodic Indirect Epoxidation Of Olefine, Xue Ying Zhang, Bao Qiu Cui, Deng Ping Gu, Wei Li Aug 2000

Cathodic Indirect Oxidation Of Organic Compounds(Ⅱ)——Cathodic Indirect Epoxidation Of Olefine, Xue Ying Zhang, Bao Qiu Cui, Deng Ping Gu, Wei Li

Journal of Electrochemistry

We described a novel cathodic indirect epoxidation system in which O 2 was first cathodically reduced to H 2O 2. Then VO(acac) 2 was oxidized by H 2O 2 homogeneously to VO(acac) 2OOH which was used to epoxidize some olefine such as maleic, fumaric and crotonic acids. Many affecting factors on the current efficiency were optimized. The research will contribute to the developments of organic electrosynthesis.

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The Study On Lithiated Titanium Composite Oxides As Negative Electrode For Lithium-Ion Battery, Xiao-Yan Yang, Shou-Nan Hua, Shu-Yong Zhang Aug 2000

The Study On Lithiated Titanium Composite Oxides As Negative Electrode For Lithium-Ion Battery, Xiao-Yan Yang, Shou-Nan Hua, Shu-Yong Zhang

Journal of Electrochemistry

Lithiated titanium composite oxides Li 4Ti 5O 12 were prepared from Li 2CO 3 and TiO 2. The XRD results of this composite oxides indicated that the compound had a spinel structure. The electrochemical behavior of lithiated titanium composite oxides was examined. The results showed that this material had an excellent cyclic capability and reversibility for lithium insertion, and had high specific capacity: the initial discharge capacity was 300 mAh·g -1 , and the reversible capacity was 100 mAh·g -1 . The discharge plateau (about 1.5 V) and the charge plateau (about 1.6 V) were very close on the voltage …

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Synthesis Of Li_(1+X)Mn_2o_4 Cathode Material For Lithium-Ion Batteries With Solution Method, Pei Song Liu, Sing Quarn Liu, Qing Li, Zhao Yong Chen, Bai Lan Zhang, Zuo Long Yu Aug 2000

Synthesis Of Li_(1+X)Mn_2o_4 Cathode Material For Lithium-Ion Batteries With Solution Method, Pei Song Liu, Sing Quarn Liu, Qing Li, Zhao Yong Chen, Bai Lan Zhang, Zuo Long Yu

Journal of Electrochemistry

The cathode materials Li 1+x Mn 2O 4 were prepared with citric acid complexing and solution impregnating methods.Structure characterization and specific surface area test were performed by means of XRD,BET methods ,the influences of calcination temperature,Li/Mn molar ratio and raw materials on the structure and electrochemical capacity of samples have beem examined.The results showed that the Li/Mn molar ratio and calcimation temperature were the key factors affecting the electrochemical capacity of cathode materias.The optimum conditions for synthesis of Li 1+x Mn 2O 4 cathode material were 0≤x≤0.05 and calcined at 750°C.The initial capacity of the sample reached 120 mAh/g and …

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The Electro-Catalytic Oxidation Of Hcooh On Electrodeposited Pd Electrode, Quan Zhou, Cunzhong Zhang, Xiaolin Lu, Zhongda Wu Aug 2000

The Electro-Catalytic Oxidation Of Hcooh On Electrodeposited Pd Electrode, Quan Zhou, Cunzhong Zhang, Xiaolin Lu, Zhongda Wu

Journal of Electrochemistry

The coherent electroplates were prepared by electro depositing Pd on supporting materials glassy carbon. The surface morphology of the electrodes was examined by SEM. The electro oxidation of HCOOH in HClO 4 solution was investigated by using cyclic voltammetry. The results show that the deposited conditions in the preparation of electrodes by electro depositing Pd affect the electrodes electro catalytic activity to the oxidation of HCOOH. The platinized Pd electrode on GC substrates using large current density is of higher catalytic activity to the oxidation of HCOOH than Pd electrode. The electro catalytic activity of PdO formed on the Pd …

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The Effect Of Anode Thickness In Sofcs With Anode Supported Ysz Film, Yi Huang Zhang, Yi Jiang, Zi Gui Lu, Yong-Lai Dong, Jing-Wang Yan Aug 2000

The Effect Of Anode Thickness In Sofcs With Anode Supported Ysz Film, Yi Huang Zhang, Yi Jiang, Zi Gui Lu, Yong-Lai Dong, Jing-Wang Yan

Journal of Electrochemistry

Solid oxide fuel cells with supported yttria stabilized zirconia electrolyte films on anode substrates of various thickness have been fabricated. The electrochemical performances of the SOFCs have been examined. The results showed that the cell performance was limited by the anodic overpotential, which is caused mainly by a concentration polarization when the anode substrate is thick. The anodic overpotential was reduced obviously as the thickness of anode substrate was decreased. As a result, the performance of the SOFC cell was improved. With a 0.5 mm anode substrate, a SOFC cell produced a power density about 0.19 W/cm 2 at 800 …

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Powder Microelectrode Modified With Nafion-Os(Bpy)_3~( 2+) And Pvp Composite And Its Catalysis For No_2 - Reduction, Pei-Fang Liu, Jia-Wei Yan May 2000

Powder Microelectrode Modified With Nafion-Os(Bpy)_3~( 2+) And Pvp Composite And Its Catalysis For No_2 - Reduction, Pei-Fang Liu, Jia-Wei Yan

Journal of Electrochemistry

The modified powder microelectrode was prepared by etching a Pt (0.1 mm diameter) disk microelectrode and filling in thus formed cavity with Nation_Os(bpy) 3 2+ /PVP composite modified carbon powder. The composite modified powder microelectrode showed cyclic voltammetric behaviors changing with the mole ratio (denoted X) of SO 3 - to Os(bpy) 3 2+ in Nafion. When X=3, a single pair of current peaks appeared near 0.6V (vs. SCE) due to Os(bpy) 3 2+/3+ redox couple. In contrast, for X=20, a pair of additional current peaks occurred near 0.4V. Both X=3 and X=20 modified powder microelectrodes strongly catalyzed the first …

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Template Synthesis And Uv-Vis Absorption Spectra Of The Nanowire Arrays Of Cadmium Chalcogenides May 2000

Template Synthesis And Uv-Vis Absorption Spectra Of The Nanowire Arrays Of Cadmium Chalcogenides

Journal of Electrochemistry

XU Shi_min, XUE Kuan_hong , KONG Jing_lin, SUN Dong_mei, FENG Yu_ying, LU Hai_yan (Dept. of Chem., Nanjing Normal Univ., Nanjing 210097, China) WANG Guang_hou (National Laboratory of Solid State Microstructures, Nanjing Univ., Nanjing 210093, China)The porous alumina membrane formed in the anodic oxidation of highly pure aluminum foil has attracted a great deal of attention in recent years [1] . It can be served as a desired template to prepare nanometer scale materials [2] due to its unique structure of discrete and cylindrical nanopores, paralleled one another, with the homogeneous size and distribution [3] . Chalcogenide semiconductors have promising prospect …

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The Study On Fabricating Thin Electrodes For Polymer Electrolyte Membrane Fuel Cells(Pemfc), Yong-Sheng Yang, Jing-Hua Liu, Chang-Peng Liu, Gong-Quan Sun, Chang-Zhi Li, Tian-Hong Lu Feb 2000

The Study On Fabricating Thin Electrodes For Polymer Electrolyte Membrane Fuel Cells(Pemfc), Yong-Sheng Yang, Jing-Hua Liu, Chang-Peng Liu, Gong-Quan Sun, Chang-Zhi Li, Tian-Hong Lu

Journal of Electrochemistry

To lower platinum loading in electrodes for polymer electrolyte membrane fuel cell,a new thin electrode fabrication technique(TEFT) was developed in this work.A series of low Pt loading electrodes with smooth and uniformed surface were fabricated by the TEFT.As a result,the maximum power density of the cell with platinum loading of 1 mg/cm 2 and Nafion 117 membrane as electrolyte was up to 0.3 W.cm -2 .Moreover,the effects of PTFE and Nafion content in cathodes on the performance of PEMFC with low Pt loading electrodes(1 mg Pt/cm 2)were examined systematically.

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Electrochemical Characterization Of Ir-Ta-Ti Metal Oxide Coated Titanium Anodes, Ting-Yong Wang, Li-Kun Xu, Guang-Zhang Chen Feb 2000

Electrochemical Characterization Of Ir-Ta-Ti Metal Oxide Coated Titanium Anodes, Ting-Yong Wang, Li-Kun Xu, Guang-Zhang Chen

Journal of Electrochemistry

Ir_Ta_Ti metal oxide coated titanium anodes of variable composition were prepared by thermal decomposition. Their micro morphorogies and electrochemical properties were characterized by scanning electron microscope, open circuit potential, cyclic voltammetry, consumption rate measurements and accelerated life test. The SEM results indicated that all coatings were of a porous and cracked_mud microstructure influenced greatly by the composition of coatings. The electrochemical measurements showed that the Ir_Ta_Ti ternary oxide_coated anodes exhibited excellent electrochemical activity and electrochemical stability in both acidic media and seawater which were affected by the composition and microstructure of the coatings. Owing to good corrosion resistance and low …

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Effect Of Different Species Of Cobalt Additive On Performance Of Nickel Hydroxide Electrode, Xian-Xia Yuan, Yin-Dong Wang, Feng Zhan Feb 2000

Effect Of Different Species Of Cobalt Additive On Performance Of Nickel Hydroxide Electrode, Xian-Xia Yuan, Yin-Dong Wang, Feng Zhan

Journal of Electrochemistry

Performances of nickel electrodes when adding or without adding Cobalt in different forms were studied, the results were interpreted by cyclic voltammetry(CV)and electrochemical impedance spectroscope(EIS). It was demonstrated that the additions of Co,CoO,CoO+Co by mechanically mixing with Ni(OH) 2 all can improve the performance of nickel electrode to some extent,and when Co is added in the form of CoO the best performance can be obtained. This can be mainly attributed to the fact that three kinds of Co additives all improved the structure of nickel hydroxide and the ability of H + in electrolyte transporting through the material,hence the reversibility …

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Electro-Oxidation Of Glyoxal To Glyoxalic Acid, Yin-Sheng Chen, Xin-Sheng Zhang, Jun Hu, Ying-Chun Dai Feb 2000

Electro-Oxidation Of Glyoxal To Glyoxalic Acid, Yin-Sheng Chen, Xin-Sheng Zhang, Jun Hu, Ying-Chun Dai

Journal of Electrochemistry

An investigation has been made to obtain the glyoxalic acid by the electrochemical oxidation of glyoxal solution with hydrochloric acid under various experimental conditions.The cell used consists of a lead cathode, a DSA anode and a cation_exchange membrane of model CM001.The current efficiency and yield for glyoxalic acid generation were 80.0% and 91.1% respectively, under optimal operating conditions: velocity of electrolyte flow 1.4 m·s -1 ,current density 450A·m -2 ,temperature 30～40 ℃,initial concentration of glyoxal and hydrochloric acid 9.1%～16.0%, 4%～6%, respectively.

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Fabrication And Examination Of Reduced Temperatrue Solid Oxide Fuel Cell Using A Supported Thin Ysz Electrolyte Substrate, Yi-Huang Zhang, Yong-Lei Dong, Yi Jiang, Zhi-Gui Lu, Jing-Wang Yan Feb 2000

Fabrication And Examination Of Reduced Temperatrue Solid Oxide Fuel Cell Using A Supported Thin Ysz Electrolyte Substrate, Yi-Huang Zhang, Yong-Lei Dong, Yi Jiang, Zhi-Gui Lu, Jing-Wang Yan

Journal of Electrochemistry

By using a cost_effective wet process,dense yttria stabilized zirconia (YSZ) films on Ni_YSZ anode substrates have been prepared successfully.The YSZ film was characterized to be around 10 μm in thickness,sufficiently dense,uniform and crack free.A single solid oxide fuel cell fabricated from the supported YSZ film electrolyte on the anode substrate and a LSM cathode prepared on the YSZ film was tested.The power density reached to 0.1 W/cm 2 at 800 ℃,showing a reasonable performance.Further analysis on both electrodes shows that the anodic overpotential was much larger than IR drop (including YSZ resistance and contact resistance) and than the cathodic overpotential.The …

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Studies On Electrochemical Synthesis Of 4,5-Disubstituted-1,2- Benzoquinones And The Reaction Mechanism, Xian-Zhang Bu, Gui-Wu Xiao, Lin Ma, Xing-Chum He, Ling-Quan Gu Feb 2000

Studies On Electrochemical Synthesis Of 4,5-Disubstituted-1,2- Benzoquinones And The Reaction Mechanism, Xian-Zhang Bu, Gui-Wu Xiao, Lin Ma, Xing-Chum He, Ling-Quan Gu

Journal of Electrochemistry

The oxidation peak potentials( E p) of alinine derivates and catechol in 0.1 mol/L KCl+15% alcohol solution were measured by cyclic voltammograms technique. The electrochemical oxidation condition was set according to the E p. Three derivates of 4,5_disubstituted _1,2_benzoquinones were prepared via electrochemical oxidation_Michael addition reaction. The possible mechanism of electrochemical oxidation_Michael addition reaction is presented.

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Cathodic Indirect Electro-Oxidation——Organic Electro-Synthesis Dimethyl Sulfone, Deng-Ping Gu, Rui-Zhi Wang, Hong-Kun Zhang, Xue-Ying Zhang, Wei Li Feb 2000

Cathodic Indirect Electro-Oxidation——Organic Electro-Synthesis Dimethyl Sulfone, Deng-Ping Gu, Rui-Zhi Wang, Hong-Kun Zhang, Xue-Ying Zhang, Wei Li

Journal of Electrochemistry

A cathodic indirect electro_oxidation system was established for indirect electro_oxidize dimethyl sulfoxide to dimethyl sulfone with electro_reduction generated H 2O 2 catalyzed by the pertungstate/tungstate(WO 5 2- /WO 4 2- )redox mediator. Influences of current density,pH,temperature,and the current efficiencies etc. on the cathodic indirect electro_oxidation of dimethyl sulfone were investigated for determining optimum reaction conditions.The current efficiency reached more than 70%.Mother_liquid could be recycled to use without pollution.

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The Influence Of The Isomerization Reactions On The Soybean Oil Hydrogenation Process, Zeljko D. Cupic Jan 2000

The Influence Of The Isomerization Reactions On The Soybean Oil Hydrogenation Process, Zeljko D. Cupic

Zeljko D Cupic

No abstract provided.

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Mathematical Simulations Of Reactors For Catalytic Conversion Of Methane To Syngas With Forced Concentration Cycling, Krzysztof Gosiewski Jan 2000

Mathematical Simulations Of Reactors For Catalytic Conversion Of Methane To Syngas With Forced Concentration Cycling, Krzysztof Gosiewski

Krzysztof Gosiewski

In this paper simulation results are presented concerning the partial catalytic oxidation of methane (PCOM) in a reactor with forced composition cycling and packed with a pelletized Pt/MgO catalyst. The reactor operates in two cycles, namely, the ‘hot’ cycle, H, during which mainly the reactants of the strongly exothermal complete combustion reaction (CH4 and O2) are supplied, and the ‘cold’cycle , C, in which mainly the components of the endothermal reforming reactions are introduced (CH4 and H2O or, optionally CO2). The simulations are supplemented with a thermodynamic analysis of the conditions of permanent carbon deposits forming in such a reactor. …

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