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Electrocatalytic Oxidation Of Some C2 Compounds (Alcohols, Aldehydes, And Carboxylic Acids) On A Pt/SbAd Electrod, Hong Li, Lincai Jiang, Xiong Jiang

Journal of Electrochemistry

The electrocatalytic oxidation behavior of some C₂ compounds(alcohols, aldehydes and carboxylic acids) on a Pt/Sb_ad electrode prepared in-situ or ex-situ UPD was investigated using pontential sweep and rotating disc electrode methods. It is confirmed that Pt/Sb_ad electrode show the most electrocatalytical active to the oxidation of aldehyde functional group and only a little activity to the oxidation of hydroxyl group, but no activity for the oxidation of carboxyl group.

The experimental results show that the activity of the Pt/Sb_ad electrode prepared by ex-situ UPD is higher than that prepared by in-situ UPD.

The limitations of the …

Oxygen Charge Transfer Reaction At The Pt/Ysz Interface, Yi Jiang, Wenzhao Li, Jingwang Yan, Shizhong Wang

Journal of Electrochemistry

Oxygen Charge transfer reaction has been investigated by various degrees of potential polarization at the Pt/YSZ interface. Anodic and cathodic charge transfer coefficients were found to be unity over the wide range of oxygen partial pressures and temperatures. While the exchange current density of the interface was found dependent on the partial pressure of oxygen in accordance with the relation: i₀=2FKr(K_O2P_O2)^1/4(1+K_O2P_O2)^1/2. Several important parameters, such as electrochemical rate constant, equilibrium constant of oxygen adsorption on Pt surface had also been extracted.

Study On Electrode Constructure And Electrical Performance Of Na/S Cell, Jianhua Yang, Jiadi Cao

Journal of Electrochemistry

A sodium wick for sodium electrode and trough shaped performs for sulfur electrode in Na/S cell were designed and investigated. The experiments suggested that the sodium wick for sodium electrode not only improved the discharge performance of cell but also reduced the quantity of sodium utilization, and increased the specific energy of Na/S cell. The trough shaped preform with alumina fibres for sulfur electrode decreased the polarization, improved the charge acceptance and prolonged the life of cell.

The Reduction Of Oxygen To Hydrogen Peroxide In An Acidic Trickle Bed Cell Using Graphite Chip Cathode, Zhaoe Lu, Guanyong Zhang, Tiangeng Zhong, Guonu Fang

Journal of Electrochemistry

The authors investigated the electrochemical reduction of oxygen to hydrogen peroxide in 0.05 mol/L H₂SO₄ solution by the trickle bed electrode using graphite chip. The bed dimension was 14×5×0.6 cm. The current efficiency and the concentration of H₂O₂ in the catholyte were determined at various current strengths and various rates of adding the electrolyte. The proper current was 0.15 A. i.e. the current density was 2.1 mA/cm² vertical cross section area of the bed. The concentration of H₂O₂ reached 7×10^-3 mol/L with the current efficiency of 0.2. If the …

Corosion Potential Imagingat The Interface Of Coating/Metal By A New Electrochemical Technique, Changjian Lin, Xiangdong Zhuo, Jidong Chen, Hui Wang, Rong-Zong Hu, Yi Song, Jian-Guang Tan

Journal of Electrochemistry

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Surface Raman Spectra Of Pyridine And 2 Mercaptopyrimidine Adsorbed On Rough Nickel Electrode, Qunjian Huang, Jinsong Gao, Xiongwei Cai, Bingwei Mao, Mingsen Zheng, Zhongqun Tian

Journal of Electrochemistry

The Raman spectra of pyridine and 2-mercaptopyrimidine (2-MP) adsorbed on bare nickel electrodes roughened by a HNO₃ etching procedure have been obtained for the first time by utilizing a highly sensitive confocal Raman microscope. Their adsorption behaviours are discussed briefly. This primary result illustrates a great potential for in-situ Raman spectroscopy in the study of chemical and electrochemical processes of transition metal surfaces.

Studies Of Surface Treatment Methods And Their Operating Mechanisms For Activation Of Hydrogen Storage Electrode, Ronghui Hu, Hanxi Yang, Shigang Lu, Shengxian Li, Jingcheng Liu, Chongzhi Yang

Journal of Electrochemistry

Surface treatment methods by use of charge discharge cycling, KBH₄ reduction and KOH etching were parallely investigated for the rapid activation of Mn(NiCoMnAl)₅ electrode. It is found that the MH electrode treated with hot and concentrated KOH solution exhibits rapid and full activation, and also gives lower discharge overvoltage, higher stable capacity and improved cycleability. It is also revealed from SEM, EDAX and ICP analysis that the KOH activation of the electrode proceeds mainly through the enrichment of mischmetal and nickel in surface to form electrocatalytically active surface for hydrogen absorption reaction, but the surface modification with KBH …

Electrocatalytic Reduction Of Nitrite In The Presence Of Complex Of Cobalt(Ⅱ) And 1,10 Phenanthroline, Jian Tong, Xiaojun Dang, Hulin Li

Journal of Electrochemistry

The electrochemistry of cobalt(Ⅱ)-1,10-phenanthroline Co(Phen)₂²⁺ complex and its ability to electrocatalyze the reduction of nitrite were studied, we found that this complex could act as a catalyst in alkaline or neutral solution for nitrite reduction. We have investigated the effect of the complex composition on electrocatalytic ability. The effects of pH value, complex concentration, regeneration and activation of electrocatalyst on the catalytic current have been studied and discussed.

Electrochemical Ploymerization Of Aniline In The Alkaline Solution And Properties Of Polymer, Shaolin Mu, Jinqing Kan, Aiguang Zhang

Journal of Electrochemistry

A deep yellow polyaniline was formed at the anodic electrode during electrochemical oxidation of aniline in the alkaline solution. The peak of oxidation potential for aniline in the alkaline solution was 0.7 V (vs.Ag/AgCl with a saturated KCl solution), which is about 0.3V less than that in the acidic solution. The results from rotating ring-disk electrode experiment show that two soluble intermediates were generated during electrochemical oxidation of aniline. The colour of the polymer in the alkaline solution is independent of applied potential and pH values. An adsorption peak was observed in the UV region at 500 nm for the …

Ftis Observation Of Twin Adsorbates Of Co On Rh Electrode In Acid Solution, Wenfeng Lin, Shigang Sun

Journal of Electrochemistry

Because of its great importance both in electrocatalysis and C1 chemistry applications, the adsorption of CO on metallic electrodes such as Pt, Pd, Au, Ag, RhF, etc. has been extensively studied by in situ infrared spectroscopy Since 1981. In all these studies only three types of CO adsorbates, i. e., linear (2090～2000 cm^-1), bridgrd (2000～1900 cm^-1) or multi-bonded (1900～1800 cm^-1) species, were identified. A different absorbate, twin CO on rhodium (Rh(CO)₂), does exist on the solid/gas interface of highly dispersed Rh or Rhn clusters on supports, this species originating a doublet at …

Hydrogen Evolution Reaction On Nanocrystalline Co-Mo/Ni Composite-Coated Electrodes, Weizeng Yu, Jie Ma, Yiming Chu, Huizhe Zhu, Hongjie Wang, Shuncheng Liu

Journal of Electrochemistry

The electrochemical behaviours of the hydrogen evolution reaction (HER) at electrodes prepared by composite coating of nanocrytstalline Co-Mo alloy particles formed by ball milling on nickel base has been sludied by using sleady-state polarization and ac impedance techiu ques. The microstructure and the size of the nanocrystals of Co-Mo alloy and the morphology of the composite-coating surface of the electrodes are measured by XRD, TEM and SEM. Results show that the nanocrystalline Co-Mo alloys prepared by high energy ball milling has high electrocatalytic activity for HER. The electrocatalytic activity for the HER is enhanced and the energy of activation for …

Electrochemical Studies On Corroding Metallic Electrodes In Frequency Domain, Chunan Cao

Journal of Electrochemistry

The electrochemical studies on corroding metallic electrodes carried out in the State Key Laberatory for Corrosion and Protection are reviewed briefly: (1) General equations of faradaic admittance under potential-control condition were derived based on the stabillity conditions of steady processes. The faradaic admittance at mixed potential then was deduced based on these equations and the electrochemical impedance spectroscopy (EIS) at corrosion potentials in the solutions containing interface inhibitors was diseussed by application of the thecetical results obtained. (2) The spectral power density (SPD) curves for electrochemical noise (EN) during the initial stagu of pitting corrosion were observed for iron and …

An Indirect Electrochemical Oxidation Of Toluene─Catalytic Effects Of Ag(Ⅰ) On Mn(Ⅱ)/Mn(Ⅲ) Couple Transition At Pt Electrode, Zhonghua Wang, Yunan Qu, Xingguo Yan, Qngmin Hua, Guacai Chen, Zhongquan Wang

Journal of Electrochemistry

The Catalytic effects of Ag(Ⅰ) on toluene oxidation by Mn(Ⅲ) as well as the anodic generation of Mn(Ⅲ) were investigated. The rates of toluene oxidation were first order with respect to both Ag(Ⅰ) and Mn(Ⅲ). Ag(Ⅱ) formed on the surface of the platinum anode when Ag(Ⅰ) was present in the anolyte, which catalyic the Mn(Ⅱ) to Mn(Ⅲ) in solution.

Study Of The Calcium-Thionyl Chloride Cells, Baohong Zhang, Meng Chen, Yingdong Wang, Dongsheng Xu

Journal of Electrochemistry

The properties of CaCl₂ SEI covered on the ca electrode surface in thionyl chloride, the influence of various salts in thionyl chloride on the porformance of the Ca anode and carbon cathode, and the function of the additive CuCl₂ and CuBr₂ to cathode in the improvement of the cathode performance were studied by AC impedance, constant current discharge, and SEM. As a result, the Ca-SOCl₂ cell was able to discharge at 50 mA·cm^-2 and the capacity reached 17.5 mAh·cm^-2.

Research On Molten Carbnate Fuel Cell, Naichao Li, Baolian Yi, Lianying Kong, Enjun Zhang, Huaxin Lin, Tianxi Qu, Yingcai Cheng

Journal of Electrochemistry

Cold-roll-milling has been evaluated as a technique for preparing porous LiAlO₂ matrices for use as a molten carbonate fuel cell electrolyte matrix. This technique produces reliable electrolyte structures with the following characteristics and advantages: ease of handling, uniform thickness, using nontoxic inorganic solvents, controlled pore size distribution, and ability to be impregnated with the alkali carbonate without fracrure.

The Molren Carbnatod Fuel Cell (MCFC) was assembled from sintered Ni electrodes and LiAlO₂ electrolyte matrix, the electrode area is 28 cm², the effect of operating conditions on cell performance was tested, it was found that the cell …

Study Of Electrochemical Behaviour Of Myoglobin Using Cyclic Voltammetry And Synchronous Fluorescence Spectroscopy, Ju Chou, Haihong Zhou, Tianhong Lu, Yue Wu

Journal of Electrochemistry

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The Inhibition Of Amphipathic S- And N-Containing Compounds On Carbon Steel Corrosion, Wei Xing, Yibin Shan, Du Guo, Tianhog Lu, Shiquan Xi

Journal of Electrochemistry

Ordered monolayers of S- and N-containing amphipathic corrosion inhibitors were depoitod onto the surfaces of carbon steel electrode with super-molecular assembly technique. The effect of molecular aggregation of monolayers on carbon steel corrosion in 0.05 mol·cm^-3 H₂SO₄ and the mechanisms of these inhibitors were discussed in details. It was found that the transport of hydrated hydrogen ion to the surface of steel depends strongly on the inhibitor molecular aggregation in the monolayers.

Development Of The High Capacity Sintered Type Nickel Positive Electrode, Guohua Yu, Shijie Zhang, Xiaolin Wang, Jingqi Wei

Journal of Electrochemistry

By improving the design and technologies of the sintered type nickel oxide positive electrode for the NiMH batteries, We do our best to increase the sinter volume and porosity,the amount of the active materals and their utilization, so we have fabricated the high capacity sintered typo nickel electrodes fitting for the NiMH battreies. The sfecitic capacity of the lot produced electrodes is up to 550 mA/cm^-3.

The Influence Of Cathode Ingredients In Zinc Chloride Type Battery On The Discharge Ability, Qi Shen, Biao Zhuang

Journal of Electrochemistry

The influence of cathodic powder ingredients in ZnCl₂ type heavy duty battery on the discharge ability has been studied, a suitable battery ingredients is founds.

Kinetic Behavior Of The Pt/Ysz Solid Electrolyte Interface Exposed To O2+He Mixture, Yi Jiang, Wenzhao Li, Lixin Cao, Jingwang Yan

Journal of Electrochemistry

Electrochemical behavior of the Pt/YSZ solid electrolyre interface has been investigated by cyclic voltammetry and linear potential sweep technique. It was found that the electrochemical adsorption of oxygen on the Pt surface follows the Temkin adsorption model. The amount of oxygen species increases logarithmically with time. Two oxygen species are electrochemically formed on the Pt surface. One is atomically adsorbed, the other probably subsurface oxygen or Pt oxide. The electrochemical reduction of adsorbed oxygen is kinetically irreverable. The cathodic peak potential is affected both by the potential sean rate and the amount of oxygen ahorbed on the surface. Kinetic parameters, …

Determination Of Transport Number Of The Modified Liclo4-(Peo)20 Polymer Electrolyte, Ruqi Zhou, Qngguo Liu, Weihua Qiu, Yun Zhang, Yuee Zhao, Leiling Yang

Journal of Electrochemistry

In this work a combination method of A.C. Impedance and chronoamperometry was used to determine the lithium ion transport number of LiClO₄·(PEO)₂₀·(PC)₁₂·(EC)₁₂ polymer electrolyte. It is known that lithium is thermodynamically unstable in non-aqueous or polymer electrolytes, leading to the formtion of a film on lithium surface, called as solid electrolyte interphase (SEI). The presence of SEI layer will greatly influence the experimental result of lithium ion transport number. The new method avoid the effect of SEI layer, and can give correct transport number of lithium ion in the electrolyte of DCIO_{4 …}

Preparation Techique Of Foamed Nickel By Electrodeposition, Xihua He, Ronghui Hu, Hanxi Yang, Zhengzhong Zuo

Journal of Electrochemistry

This paper describes the preparation technique and operation conditions for manufacturing foamed nickel by chemilcal pretreament, electrodeposition and heat treatment. The foamed nickel made in this method showed high porosity, uniformity and considerable strength and tenacity,applicable for various secondary battery electrodes.

The Electrochemical Behavior Of C60-Chemically Modified Poly(N-Vinylcarhzole)In 1 Mol/L Liclo4-Thf Solutions, Yu Chen, Zuen Huang, Ruifang Cai, Fupin Zhang

Journal of Electrochemistry

The electrochemical behavior of C₆₀-PNVC copolymer in 1 mol/L LiClO₄-THF solutions has been studied by cyclic voltammetry. The results demonstrated that there are considerable differences of electronic structure between PNVC (Poly (N-vinylcarbazole)) and C₆₀-PNVC copolymer, this being consistent with the ESR results and the oxidstion-reduction activarion of pure PNVC by C₆₀-chemical modification. In the potential region, 1.3V～-3.5V, five steps, 0. 90V/0.60V, 0.20V/0.00V, -1.05V/-1.30 V, -1.25V/-1.75 V, -2.00V/-2.50V, of oxidation/reduction proceases were indicated in the cyclic voltammetry for pure PNVC, whereas seven steps, 0.20V/0.20V, -0.30V/-0.50 V, -0. 60V/-0.60 V, -0.80V/-1.10 V, -1.95V/-2.10 V, …

Study On The Manufacture Of Pt/C Gas-Diffusion Electrodes, Yonglin Ma

Journal of Electrochemistry

The various methods of manufacturing gas-diffusion electrodes are reviewed and a new method of preparing the Pt/C electrocatalyst and the gas-diffusion electrodes is explored in this paper. The electrochemical performance of resulting electrodes in concentrated phosphoric acid for oxygen reduction at 150℃ are compared with the commercial electrode which purched from Giner Inc. (U. S. A). The results show that the performance of the Pt/C electrodes which manufactured by the method in this paper has been greatly improved. Therefor, a fuel cell using such electrodes has high industrial value.

Simultaneous Detection System Combining Studies Of Programmedpotential Step Technique And Time-Resolved Ftir Spectroscopy, Shigang Sun, Xiaoyu Chen, Guoqiang Lu, Wenfeng Lin, Nanhai Li, Shenpei Chen, Hongping Dai, Jiqian Mu

Journal of Electrochemistry

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A Photoelectrochemical Investigation Of A.C.Modulated Passive Films On 304 Stainless Steel In Weak-Alkaline And Neutral Solution, Tianbao Du, Chunan Cao, Jiakang Yu, Haichao Lin

Journal of Electrochemistry

A photoelectrochemical investigation has been carried out on AISI 304 stainless steeI AV modulated passive film in 0.1mol/L Na₂B₄O₇ and 0.5 mol/L Na₂SO₄ solution. Photo current curve depends on the potential, passive condition and testing solutions. The results of the measurements indicate that the photoresponse is determined by the defects in the electronic structure of the films whenthe defects lead to localized states in the bandgap region. It is concluded that the passive film on AISI 304 stainless steel is in a highly disordered amorphous state.

Growth Kinetics And Breakdown Of Passive Films On Rebar Electrodes In Simulated Cement Pore Solution, Wei Chu, Yuanxiang Shi, Baoming Wei, Yong Yang, Xuguang Chen, Zugeng Lin

Journal of Electrochemistry

The growth kinetics and breakdown of passive films on REBAR electrodes insimulated cement solution (pH=12.5 and 13.8) have been investigated using in situ photoelectrochemical methods and potential step method. The results show that there are two mainstages in the growth of the film, with two rate functions characterized by linear relation between thefilm thickness and the direct logarithm of time. There is a sign in laser-scanning photoelectrochemical microscopic image just before the passive film breaks down. The addition of inhibitor NaNO₂ changes the growth kinetics and thickness of the film, and therefore improves the resistance of pitting corrosion induced …

Fabrication And Electrochemical Behaviors Of Thin Films Of Polyaniline By Langmuir-Blodgett Technique And Electropolymerization, Benzeng Hua, Zhaoxiong Xie, Yanzhen Chen, Yunhong Zhang

Journal of Electrochemistry

Hydrogen-bond between stearic acid and aniline in subphase lead to Langmuir monotayers of stearic acid-aniline, the molecular area of stearic acid-aniline is 26 nm². With surfacepressure increased into 50 mN/M, the hydrogen-bond would be rearranged, aniline molecular transales into vertical from horizontal, surface pressure decreased quickly. A new kind of Langmuirmonolayer is formed instead of collapse, it's molecular area decreases into 24 nm² and thicknessin creases with 0.25 nm. After electroreduction of L-B films depeited onto the surface of SnO₂ electrode, anilne layers between two stear acid matix could be polymerized into thin films of polyanilne. …

Cyclic Voltammetric Calorimetry Studying The Deposition Of Copper Of Pt Electrodes, Yongchun Zhu, Robin. H. J. Clark

Journal of Electrochemistry

In the present paper, cyclic voltammetric calorimetry has been used to study thedeposition of copper on platinum electrode from LiClO₄ aqueous solution. Cyclic voltammetric thermogram and cyclic voltammetric differential thermogram show that the deposition of copper on theelectrode is an exothermal process with a strong interaction between copper and platinum layer (-3227.0 kJ /mol). The electrochemical oxidation of the deposited copper is composed of twoprocesses: an endothermal activation process with 747.0 kJ/mol of activation enthalpy, and an exothermal oxidation reaction with -189.9 kJ/mol of the reaction enthalpy, which are accord with the data from the theoritical estimation and thermodynamic …

Electrochemical Behaviors Of The Loaded Stainless Steel In Dilute Thiosulphate Solution, Changjian Lin, Zude Feng, Fuling Lin, Fayang Wang, Jianguang Tang, Yuanhui Wang

Journal of Electrochemistry

The electrochemical behavior of 18/8 stainless steel in dilute thiosulphate solutionduring strained loading was studied by various electrochemical techniques and scanning electronmicroscope. It is evidenced that the corrosion activity of stainless steel increased with strained loading. The dynamic process of repassivation, which may datermine the initiation, the cease and development of the stress corrosion cracking for stainless steel, was strongly influenced by both electrochemical andloading conditions. Pitting corrosion may locate preferentially on the sites which was suffered mostloading. The propagation of pitting corrosion of stainless steel may induce stress corrosion crakingunder certain conditions.