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Articles 1501 - 1530 of 1756

Full-Text Articles in Physical Chemistry

Study On The Effect Of Sodium Ion On Cycle Performance Of Lithium/Improved Graphite Lithium Ion Cell, Wen-Huang Huang, Yu-Shun Yan, Chun-Rong Wan, Chang-Yin Jiang May 2000

Study On The Effect Of Sodium Ion On Cycle Performance Of Lithium/Improved Graphite Lithium Ion Cell, Wen-Huang Huang, Yu-Shun Yan, Chun-Rong Wan, Chang-Yin Jiang

Journal of Electrochemistry

The different concentration of Na+ was introduced into the non-aqueous eletrolyte system EC/DEC/LiClO 4 with 4A molecular sieve and lithiated 4A molecular sieve, by which the trace amount of water was removed. The concentrations of Na+ and Li+ were determined by atomic adsorption spectrometry. The cycle performance of lithium/improved graphite cells was then examined by charging and discharging under the constant electric current. The results demonstrated that the cycle performance of the cells was destroyed by the high concentration of Na+ under the small electric current. With the increase of electric current the cell became less …


The Studies On Nanosized Materials For Lithium Ion Batteries, Hong Li, Jing-Ze Li, Li-Hong Shi, Guang-Yan Zhu, Qing Chen, Wei Lu, Xue-Jie Huang, Li-Quan Chen May 2000

The Studies On Nanosized Materials For Lithium Ion Batteries, Hong Li, Jing-Ze Li, Li-Hong Shi, Guang-Yan Zhu, Qing Chen, Wei Lu, Xue-Jie Huang, Li-Quan Chen

Journal of Electrochemistry

Our recent works about nanosized materials for lithium ion batteries are reported, including the synthesis of nanosized Sb, SnSb, CuSnx, Si and CuS, their electrochemical performance as anode or cathode active materials, the variation of crystal structure and morphology during discharge and charge cycling. In addition, the self-plasticization of lithium salt with nanosized anion ion in polymer electrolyte, the influence of the electrochemical Li-doping on the Raman spectra and photoluminescence of nano-Si are also introduced. Furthermore, the relationship between intrinsic properties of nanosized materials and their electrochemical behaviors are discussed. The prospect of nanosized materials for lithium ion …


Determination Of Kinetic Parameters Of Enzyme-Immunoelectrode For Sec Assay, Sa-Ying Dong, Xin-Miao Liu, Yuan-Zhi Wang, Guang-Zhang Chen, Ming-Xiang Lv, Bo-Yi Tian May 2000

Determination Of Kinetic Parameters Of Enzyme-Immunoelectrode For Sec Assay, Sa-Ying Dong, Xin-Miao Liu, Yuan-Zhi Wang, Guang-Zhang Chen, Ming-Xiang Lv, Bo-Yi Tian

Journal of Electrochemistry

Reaction mechanism of enzyme immunoelectrode is studied by potentiostatic. Rotating disk electrode is used to determine the controlling step of bioelectrode. Under different potentials and different modifying conditions, kinetic parameters of bioelectrodes were measured on the base of electrochemical impendance spectra. At the same time, these parameters are compared and discussed.


The Influence Of Surface Diffusion Of Adsorbed Intermediate On Hydrogen Evolution Reaction At Pt/Nafion Composite Electrodes, Wei-Yi Tu, Lei Su, Wen-Jun Liu, Bing-Liang Wu May 2000

The Influence Of Surface Diffusion Of Adsorbed Intermediate On Hydrogen Evolution Reaction At Pt/Nafion Composite Electrodes, Wei-Yi Tu, Lei Su, Wen-Jun Liu, Bing-Liang Wu

Journal of Electrochemistry

The decrease of over-potential of hydrogen evolution reaction at Pt black powder/Nafion microelectrode, comparing that of the Pt microdisk/Nafion electrode, was evident from the polarization curves of the Pt microdisk/Nafion electrode, platinized Pt micrdisk/Nafion electrode and Pt black powder/Nafion microelectrode. It is also evidenced by a plane Pt electrode with an additional free Pt surface. The surface diffusion and the surface recombination reaction of the adsorbed intermediate at the free surface of the Pt particles were supposed. It is an additional reaction path that induced the decrease of the concentration of the adsorbed intermediate. Thereby, the over-potential decreased.


Powder Microelectrode Modified With Nafion-Os(Bpy)3Â 2+ And Pvp Composite And Its Catalysis For No2- Reduction, Pei-Fang Liu, Jia-Wei Yan May 2000

Powder Microelectrode Modified With Nafion-Os(Bpy)3Â 2+ And Pvp Composite And Its Catalysis For No2- 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)32+/PVP composite modified carbon powder. The composite modified powder microelectrode showed cyclic voltammetric behaviors changing with the mole ratio (denoted X) of SO3- to Os(bpy)32+ in Nafion. When X=3, a single pair of current peaks appeared near 0.6V (vs. SCE) due to Os(bpy)32+/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 …


Technical Investigaton Of Thin-Film Plasticizing Lithium Ion Battery, Xin-Ping Ai, Xin-Lin Hong, Quan-Feng Dong, Sheng-Xian Li, Han-Xi Yang May 2000

Technical Investigaton Of Thin-Film Plasticizing Lithium Ion Battery, Xin-Ping Ai, Xin-Lin Hong, Quan-Feng Dong, Sheng-Xian Li, Han-Xi Yang

Journal of Electrochemistry

A number of polymer materials as candidates of host matrix of plastic polymer electrolyte were examined and techniques for preparation of thin-film electrolyte were reported. The results showed that the polymer electrolyte prepared with P(VDF-HFP) copolymer as host matrix and DBP as plasticizer exhibit the satisfactory mechanical strength and ionic conductivity. In comprison with liquid electrolyte systems, thin-film lithium ion battery has almost similar charge-discharge capacity and cycleability. The manufacture methods and the technical factors in making plasticizing lithium ion battery were also described in details.


Study On Carbon From Pyrolyzing Phenol-Formaldehyde Resin For The Negative Electrode Of Li-Ion Secondary Battery, Zhi-Yuan Tang, Xin-Guo Zhuang, Yu-Mei Zhai, Jian-Gang Li, Jian-Jun Xue, Chun-Yan Liu May 2000

Study On Carbon From Pyrolyzing Phenol-Formaldehyde Resin For The Negative Electrode Of Li-Ion Secondary Battery, Zhi-Yuan Tang, Xin-Guo Zhuang, Yu-Mei Zhai, Jian-Gang Li, Jian-Jun Xue, Chun-Yan Liu

Journal of Electrochemistry

Li-ion secondary batteries negative electrodes were prepared by low temperature (<1 000 ℃) pyrolysis of commercial phenol-formaldhyde resin. A thermogravimetric analysis (TGA) and an X-ray diffraction (XRD) studies were peoformed for the pyrolytic carbonaceous materials. The results indicated that these samples are amorphous polyacenic structure materials. With increasing pyrolytic temperature, these materials become structurally order, and the first charge-discharge special capacities reduce. The specific capacities base on pyrolytic temperature, involving lithium storage nanometer cavities.


Preparation And Characteristics Of A Enzyme Electrode Based On Immobilization Of Tyrosinase In Electropolymerized Polypyrrole Film, Liu-Shui Yan, Qia Wei, Cheng-Yi Wang, Rong-Rong Shi, Xiao-Tong Ma May 2000

Preparation And Characteristics Of A Enzyme Electrode Based On Immobilization Of Tyrosinase In Electropolymerized Polypyrrole Film, Liu-Shui Yan, Qia Wei, Cheng-Yi Wang, Rong-Rong Shi, Xiao-Tong Ma

Journal of Electrochemistry

A sensitive and stable amperometric enzyme electrode was constructed, based on the immobilization of tyrosinase in potentiostatically electropolymerized polypyrrole film at a platinum electrode. The influence of pH and potential on immbilization was discussed. SEM micrographs and CV curves of films obtained before and after incorparation of tyrosinase molecular were analyzed and compared each other. The enzyme electrode responds linearly to p-cresol over a concentration range of 5×10 -8 ~1×10-6 mol/L with an optimum pH of 6.6, It exhibited kinetic characteristics of the typical enzyme-catalyzed reaction with an apparent Michaelis constant of 2.2 ×10-5 mol/L.


An Investigation On The Corrosion Potential Imaging At The Interface Of Concrete/Reinforcing Bar In Corrosion Media, Rong-Zong Hu, Chang-Jian Lin, Xiang Zhou, Jian-Guang Tan, Xiong-Chao Zhao May 2000

An Investigation On The Corrosion Potential Imaging At The Interface Of Concrete/Reinforcing Bar In Corrosion Media, Rong-Zong Hu, Chang-Jian Lin, Xiang Zhou, Jian-Guang Tan, Xiong-Chao Zhao

Journal of Electrochemistry

The iron array electrode covered with concrete as a new electrochemical technique is applied to map the potential imaging and to investigate on the iron electrode corrosion process under concrete: In Cl- solution the corrosion of the iron array electrode covered with concrete had been prevented for a short term since the concrete protection, but the corrosion still occurreed and developed after immersed for a long time. In SO42- solution although the sample had being immersed for a long time and the concrete was possibly broken, the corrosion did not develop. In Cl- solution the corrosion …


Template Synthesis And Uv-Vis Absorption Spectra Of The Nanowire Arrays Of Cadmium Chalcogenides, Shi-Min Xu, Kuan-Hong Xue, Jing-Lin Kong, Dong-Mei Sun, Yu-Ying Feng, Hai-Yan Lu, Guang-Hou Wang May 2000

Template Synthesis And Uv-Vis Absorption Spectra Of The Nanowire Arrays Of Cadmium Chalcogenides, Shi-Min Xu, Kuan-Hong Xue, Jing-Lin Kong, Dong-Mei Sun, Yu-Ying Feng, Hai-Yan Lu, Guang-Hou Wang

Journal of Electrochemistry

The porous alumina membrane formed in the anodic oxidation of highly pure aluminum foil has attracted a great deal of attention in recent years. It can be served as a desired template to prepare nanometer scale materials due to its unique structure of discrete and cylindrical nanopores, paralleled one another, with the homogeneous size and distribution. Chalcogenide semiconductors have promising prospect in the applications of photovoltaic and photoconducting devices and have been extensively exploited for many years. Olbright and his co-workers studied experimentally and theoretically the optical nonlinearties of CdSxSe1-x-doped glass; Britt and Ferekides reported that …


Electrochemical Quartz Crystal Microbalance Study On The Promoted Electron Transfer Process At Gold Electrode, Xia-Qin Wu, Zhe-Su Wang, Xiao-Yun Meng, Zong-Rang Zhang May 2000

Electrochemical Quartz Crystal Microbalance Study On The Promoted Electron Transfer Process At Gold Electrode, Xia-Qin Wu, Zhe-Su Wang, Xiao-Yun Meng, Zong-Rang Zhang

Journal of Electrochemistry

The adsorption behavior of amino acids, such as L-cysteine, histidine and arginine at gold-quartz crystal microbalance (Au-QCM) was investigated. The adsorption quantity of cysteine is more appreciable than others because of the stronger interaction between its thiol group and the gold electrode surface. The electron-transfer process of superoxide dismutase (SOD) in presence of cysteine at Au-QCM has also been studied using the electrochemical quartz crystal microbalance (EQCM) technique which reveals clearly the quasi-reversible electron-transfer process accompanied by the frequency shift cycle. The reversible adsorption and disorption processes are discussed.


Effects Of Temperature On The Proton Diffusion Of Doped Ni(Oh)2, Jian-Hua Liu, Jing-Wu Yang, Zhi-Yuan Tang May 2000

Effects Of Temperature On The Proton Diffusion Of Doped Ni(Oh)2, Jian-Hua Liu, Jing-Wu Yang, Zhi-Yuan Tang

Journal of Electrochemistry

The Chronoamperometry of powder spherical Ni(OH)2 microelectrode was used to study the proton diffusion coefficients of Ni(OH)2. The proton diffusion coeefficients and the apparent diffusion active energy in anode and cathode processes at different temperature were obtained. Compared with pure Ni(OH)2, the apparent diffusion active energy (Ea) of Ni(OH)2 doped with Co and Co + Zn was decreased and the diffusion constant (Do) was increased in the anode and the cathode processes, respectively, the effect of Co was greater. In contrast, for Ni(OH)2 doped with Zn, its Ea …


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

Journal of Electrochemistry

A cathodic indirect electro-oxidation system was established for indirect electro-oxidize dimethyl sulfoxide to dimethyl sulfone with electro-eduction generated H2O2 catalyzed by the pertungstate/tungstate (WO52-/WO42-) 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.


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 …


Studies Of Abnormal Infrared Effects Of Nanometer Thin Films Of Transition Metals And Alloys In Acid Solutions, Shi-Gang Sun, Ming-Sen Zheng, Guo-Qiang Lu, Li-Rong Cai, Sheng-Pei Cehn, Xiao-Yin Xiao Feb 2000

Studies Of Abnormal Infrared Effects Of Nanometer Thin Films Of Transition Metals And Alloys In Acid Solutions, Shi-Gang Sun, Ming-Sen Zheng, Guo-Qiang Lu, Li-Rong Cai, Sheng-Pei Cehn, Xiao-Yin Xiao

Journal of Electrochemistry

The adsorption of CO on electrodes of nanometer thin films of transition metals (Pt, Pd, Rh, Ru) and alloys (PtPd, PtRu) prepared under cyclic voltammetric conditions has been studied by in situ FTIR spectroscopy. The abnormal infrared effects (AIREs) have been explored as a novel and general phenomenon. The AIREs consist mainly in the inversion of the direction of IR band and the significant enhancement of IR absorption by adsorbed CO species. It was revealed that the enhanced IR absoroption of adsorbed species in AIREs depends strongly on the nature of metal or alloy, and on the structure and the …


Investigations Of Lithium Ion Battery Electrolyte Solution, Jing-Li Han, Qing-Guo Liu Feb 2000

Investigations Of Lithium Ion Battery Electrolyte Solution, Jing-Li Han, Qing-Guo Liu

Journal of Electrochemistry

Synthesis and electrochemical investigations of {LiB[(SO3)C6H3(O)(COO)]OC6H5} in EC/DMC or DMSO/PC mixtures are presented.


Studies Of The Preparation Of Electrodes From Lead Carbonate For Lead-Acid Battery Ⅱ. The Preparation Of Paste Electrodes, Zhong-Xu Dai, Di-Hua Wang, Hao-Hao Ke, Jin-Yun Zou, Yun-Hong Zhou Feb 2000

Studies Of The Preparation Of Electrodes From Lead Carbonate For Lead-Acid Battery Ⅱ. The Preparation Of Paste Electrodes, Zhong-Xu Dai, Di-Hua Wang, Hao-Hao Ke, Jin-Yun Zou, Yun-Hong Zhou

Journal of Electrochemistry

The positive and negative pastes were prepared by mixing PbCO3 and H2SO4 solution as well as relative additives, respectively. The effects of the various formation methods and the charge/discharge conditions on discharge capacity and active material utilization of both electrodes were examined. The results indicate that the performance of the positive electrode formed at 2.0 mA/cm2 is better than that formed at higher current density under the same charge/discharge condition, the PAM utilization reaches 74.4 % under discharging at 2.0 mA/cm2; and the property of the negative electrode formed by unsymmetrical square wave …


Sprayed And Thermally Evaporated Carbon Films As Anodes For Lithium Ion Batteries, Shu-Gao Zhang, M.Schleich Donald Feb 2000

Sprayed And Thermally Evaporated Carbon Films As Anodes For Lithium Ion Batteries, Shu-Gao Zhang, M.Schleich Donald

Journal of Electrochemistry

Carbon films were made using spray-thermal evaporation from a kind of pyrolytic carbon powder. The films obtained with graphite structure were both potentio-statically and galvanostaically tested. Cycling patterns indicated a reduction peak on the first cycle corresponding to the formation of solid electrolyte interface, and the capacity values and x values were quite acceptable compared to theoretical ones when charging-discharging current density was suitable. Based on the experimental results, the obtained carbon films could be used as anode materials for relatively determining the electrochemical performances of cathode materials.


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 (Ep) 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 Ep. 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.


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/cm2 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/cm2) were examined systematically.


Study On Preparation Of Coarse And Fine γ-Lialo2 Mixed Powder Used For Mcfc Matrix, Hua-Xin Lin, Bao-Lian Yi, Lian-Ying Kong, En-Jun Zhang, Li Zhou, Feng-Xia Wang Feb 2000

Study On Preparation Of Coarse And Fine γ-Lialo2 Mixed Powder Used For Mcfc Matrix, Hua-Xin Lin, Bao-Lian Yi, Lian-Ying Kong, En-Jun Zhang, Li Zhou, Feng-Xia Wang

Journal of Electrochemistry

Coarse α-LiALO2 powder was transferred completely to γ-LiAlO2 at 900 ℃ for ten hours. Fine γ-LiALO2 powder was prepared by “chloride” synthesis. MCFC matrix was fabricated by mixing the coarse and fine γ-LiALO2 powder and by tape cast. The out'put voltage of the cell assembled with the matrix was 0.85 and 0.75 V respectively at 200 and 300 mA/cm 2, and power density was about 250 mW/cm2. The performance of the matrix fabricated with the mixed powder was obviously more advanced than that of the matrix fabricated with only coarse γ-LiALO2 powder.


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 …


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/cm2 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 …


An Eis Study On The Synergetic Filming Between Cathodic Protection And The Corrosion Inhibitor, Yong-Tao Zhao, Jian-Hua Wu, Jian-Hua Qian, Hui Yu Feb 2000

An Eis Study On The Synergetic Filming Between Cathodic Protection And The Corrosion Inhibitor, Yong-Tao Zhao, Jian-Hua Wu, Jian-Hua Qian, Hui Yu

Journal of Electrochemistry

The electrochemical impedance spectroscope (EIS) of 907A steel in seawater was investigated to study the film formation and destruction. The corrosion protection mechanism of the synergy interaction between cathodic protection and YKI-5 corrosion inhibitor (a mixture of polyhydric alcohol phosphate ester, phosphate and polyphosphate) is discused. Typical EIS spectral changes were clearly observed during the film formation and destruction processes. EIS results indicated that the film seemed to formed a multi-layered structure which consist of an inner layer (this may be an inhibitor-metal complex layer) and many outer layers of calcareous deposits. The film possesses of good persistency under the …


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 450 A·m-2, temperature 30~40 ℃, initial concentration of glyoxal and hydrochloric acid 9.1%~16.0%, 4%~6%, respectively.


Studies On Methods Of Fuel Cells Electrodes Preparation, Jun Gu, Sheng Sui, Guang-Qiang Li, Zhitong Sui Nov 1999

Studies On Methods Of Fuel Cells Electrodes Preparation, Jun Gu, Sheng Sui, Guang-Qiang Li, Zhitong Sui

Journal of Electrochemistry

In fuel cells, the structure of electrodes is an important factor which effect the cell performance. To improve the structure and the performance of electrodes, a new method of providing fuel cell electrodes is proposed in this paper. PTFE (polytetrafluoroethylene) and ethyne black was ground for about half an hour in a high-speed grinder, then the catalyst was added into the grinder and milled for an hour. This milled catalyst was transferred into a mixer followed by the addition of surface-active agent. After a suspension was formed, it was filtered under vacuum condition.Then a thin uniform filter-cake of the catalyst …


The Electrochemical Behaviors Of Superoxide Dismutase At Promoter Modified Gold Electrode, Xia-Qin Wu, Xiao-Yun Meng, Zhe-Su Wang, Zong-Rang Zhang Nov 1999

The Electrochemical Behaviors Of Superoxide Dismutase At Promoter Modified Gold Electrode, Xia-Qin Wu, Xiao-Yun Meng, Zhe-Su Wang, Zong-Rang Zhang

Journal of Electrochemistry

The electron-transfer process of superoxide dismutase was investigated by cyclic voltammetry at the 4,4'-dithiodipyridine, L-cysteine, histidine and arginine modified gold wire electrodes repectively. The quasi-reversible behavior was observed at L-cysteine modified gold electrode. An irreversible electrochemical behavior has been observed at hisdinine modified gold wire electrode.


Study On Electrochemical Reduction Properties Of Nitrobenzene, Chu-Na Ma, Wen-Kui Zhang, Hui Huang, Yong-Ping Gan Nov 1999

Study On Electrochemical Reduction Properties Of Nitrobenzene, Chu-Na Ma, Wen-Kui Zhang, Hui Huang, Yong-Ping Gan

Journal of Electrochemistry

The electrochemical reduction characteristics of nitrobenzene was extensively investigated by using the techniques such as quasi-steady-state polarization, cyclic voltammetry, fast linear potential sweep method and chronoamperometry in this paper. The electroanalytic properties of Cu, Cu-Hg and Cu-Ni electrodes were evaluated. Based on the study of the transient steping behaviour of nitrobenzene to PAP, the reduction mechanism was discussed. The results showed that the transition steps existed on the electrochemical reduction of nitrobenzene in acidic solution, the reactant is also absorbed on electrodes surface. The control step in the reduction of nitrobenzene was ascribed to the diffusion of nitrobenzene and its …


A Novel Reaction Region Moving Electrode System For Electrochemical Power Sources, Jin-Kua You, Que Tu, Zheng-Jian Wang, Jie Sun, Zu-Geng Lin Nov 1999

A Novel Reaction Region Moving Electrode System For Electrochemical Power Sources, Jin-Kua You, Que Tu, Zheng-Jian Wang, Jie Sun, Zu-Geng Lin

Journal of Electrochemistry

In most of practical rechargeable batteries, charging/discharging process is always concerned with phase-transformation in the solid state. Due to the irreversibility of the phase-transformation, the cyclic performance of the rechargeable batteries are limited. In this paper, a novel reaction-region moving counter electrode system is constructed in our laboratory. The electrode system is operated at room temperature and cycled in solid-liquid phase during charging/discharging processes. With this electrode, the metal-complexes are firstly deposited (i.e. charging process) on the nearest working electrode and gradually extended to those another working electrodes several centimeters away from the counter electrode. The deposite is dissolved again …


High Performance Proton Exchange Membrane Fuel Cells, Jing-Rong Yu, Bao-Lian Yi, Ming Han, Xiao-Liang Cheng, Zhi-Gang Shao, Jing-Xin Zhang Nov 1999

High Performance Proton Exchange Membrane Fuel Cells, Jing-Rong Yu, Bao-Lian Yi, Ming Han, Xiao-Liang Cheng, Zhi-Gang Shao, Jing-Xin Zhang

Journal of Electrochemistry

Proton-exchange membrane fuel cells(PEMFC) using a perfluorosulfonic acid proton exchange membrane as an electrolyte can simplify water and electrolyte management. In this paper, the effects of thickness of PEM on the performance of PEMFC were studied. The Nafion-112 PEM and low platinum loading E-TEK electrode yielded very high power density, of the order of 0.95 W/cm2. The energy-conversion efficiency, the degree of platinum utilization and stability for PEMFC using Nafion 112 and E-TEK electrode were also investigated.