Chemistry Commons^™

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 …

The Applications Of Poap Ni2+ Films Modified Electrode As Sensor For Alcohol, Bingzeng Hua, Wenyun Hu, Yanzhen Chen

Journal of Electrochemistry

POAP Ni²⁺ films modified electrode can electrocatalyzes significantly the oxidation of alcohol. The modified electrode can be used as the electrochemical sensor for the detection of alcohol. But the oxidation of alcohol is effected by the thickness of films、the concentration of nickel ion in films, pH of electrolyte, as well as temperative. All of those conditions have been studied in order to achieve stable response current during the oxidation of alcohol, and the relation between concentration and current has been made. At last the major characteristic parameters, such as the low limitation of concentration, the response time, the ability …

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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Problems On The Study Of Anodic Films On Pb In Sulfuric Acid Solution (Ⅱ), Houtian Liu, Qunzhou Wang, Yongqin Wan, Weifang Zhou

Journal of Electrochemistry

The conditions for the growth of the different phases in the anodic Pb(Ⅱ) film on Pb in sulfuric acid solution were discussed.

Status Of The Research And Development For Fuel Cell Technology Abroad, Naichao Li, Baolian Yi

Journal of Electrochemistry

Status of the research and development for fuel cell technology abroad was overviewed, and at the aim of accelerating the research and development for fuel cell technology in China, the corresponding stategy for our country was recommended.

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.

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 …

In Situ Studies Of Copper Electrodepostion On Hopg By Using Ecstm, Zhaoxiong Xie, Bingwei Mao, Xiangdong Zhuo, Jiqian Mu, Zhaowu Tian

Journal of Electrochemistry

In this paper, copper electrodepostion on HOPG had been in situ studied by using a homebuilt electrochemical scanning tunneling microscopy (ECSTM). Three dimensional nucleation and subsequent growth of copper crystals were found as the initial stage of copper deposition on HOPG. In the case of lower overpotential or lower concentration of Cu²⁺ , the bulk deposited copper layer tended to form smooth terraces, and grow at the edge of steps. The terraces were stable to some extent, which made it possible to be observed with atomic resolution. At a higher overpotential, the crystal size of copper were somehow smaller. …

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 …

A Study Of The Electroplated Fe-Cr-Ni Alloy Microstructure, Donglin Li, Jianping Liu, Fangzhou Guo, Jianrong Hua

Journal of Electrochemistry

The microstructure of the electroplated Fe-Cr-Ni alloys from the mixed carboxylic acid solution containing Cr(Ⅲ) and additives were determined with XRD and SEM. Experimental results showed that, under the experimental condition, the phase component, structure of Cu base electroplated Fe-Cr-Ni alloys had a critical thickness, which was 11 μm and a critical Ni content, which was 32%. Organic additives, formic acid or polyethylene Glycol, mainly affected the surface, cross section morphology of the electroplated Fe-Cr-Ni alloys. Adding Mo to the electroplated Fe-Cr-Ni alloys led to remarkable corrosion resistance in concentrated HCl.

Petrochemical Analysis By Remote Fiber-Optic Raman Spectroscopy And Partial Least Squares Regression Analysis, Philip Edmund Flecher Jr.

Chemistry & Biochemistry Theses & Dissertations

A dispersive Raman system with charge coupled device (CCD) detection, distributed Bragg reflector (DBR) diode laser excitation, and a fiber optic probe has been developed for the rapid analysis of petrochemicals and fuels. Initially, mock petroleum fuels with analyte concentrations from 1.S - 16% were prepared and analyzed with the system. The inability of the original index guided diode laser to maintain a constant frequency during the mock petroleum analysis was a recurrent problem. The DBR laser was subsequently shown to have stability superior to index guided lasers, and was used in the remainder of the research.

Real gasoline samples …

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.

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.

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 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.

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.

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 …}

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 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, …

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.

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 …

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, …

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 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 …

Microhollow Cathode Discharges, K. H. Schoenbach, R. Verhappen, R. Tessnow, F. E. Peterkin, W. W. Byszewski

Bioelectrics Publications

The current–voltage characteristics of hollow cathode discharges and their predischarges in argon under dc and pulsed conditions were found to have a positive slope at pressures up to approximately 50 Torr, and currents up to 20 mA, at a hole diameter of 0.7 mm. In this range of pressure and current, parallel operation of hollow cathode discharges, without ballast, was demonstrated. Scaling to higher pressure is possible by reducing the hole diameter. Pulsed experiments with an array of cathode rings of 75 μm diameter allowed us to obtain parallel operation of more than 50 discharges at a pressure of 350 …

Biodegradation Of Nonionic Surfactants And Effects Of Oxidative Pretreatment, Craig D. Adams, S. Spitzer, R. M. Cowan

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The aerobic biodegradability of nonionic, ethoxylated surfactants and model compounds, and the effect of advanced oxidation pretreatment on the biodegradability of the biorefractory surfactants were examined. Bioassays conducted using a mixed microbial seed showed that the linear primary alcohol ethoxylates, the fatty acid ethoxylates, and also polyethylene glycol were all degradable. The biomineralization of the linear secondary alcohol ethoxylate, ethylene oxide/propylene oxide block copolymer, and alkylphenol ethoxylate was observed to be inhibited to varying degrees. Additional bioassays were conducted on model compounds to examine the effect of specific structural components on biodegradability. Advanced oxidation pretreatment using hydrogen peroxide in combination …

Treatability Of S-Triazine Herbicide Metabolites Using Powdered Activated Carbon, Craig D. Adams, Tammy L. Watson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Widespread use of s-triazine herbicides such as atrazine, simazine, and cyanazine has led to the contamination of many ground-water and surface-water supplies with the parent compounds as well as by primary metabolites (e.g., deethylatrazine, deisopropylatrazine, and deethylcyanazine). Ozonation has been shown to produce many of the same byproducts. Activated carbon adsorption has been designated by the U.S. Environmental Protection Agency as the best available technology (BAT) for the treatment of herbicides in drinking water. Little data is available, however, on the applicability of activated carbon treatment for the control of the primary degradation products of herbicides. In this study, the …