Physical Chemistry Commons^™

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 …

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.

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.

A Study On Performance Of Electroless Nickel Coatings Containing Low Phsphorus, Huilin Guo, Xinguo Hu, Guipin Su

Journal of Electrochemistry

The low phosphorus coatings (LP) had superior corrosion resistence to that of high phosphorus (HP) in alkaline and neutral NaCl solutions. The microhardness of the coatings increaed from 454 Hv to 890 Hv when they were heated at 350℃ for one hour. Two exothermic peaks were observed at 341.6 ℃and 406.2 ℃, which respectively corresponded to form the new phases Ni₅P₂ and Ni₃P in the differential thermal analysis. The atomic structure of as-deposited coatings in the terms of X-ray diffraction had confirmed that the coatings coasisted of extremely fine crystallites.

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 …

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.

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 …

Application Of Electroanalytical Chemistry In Heteropoly Compounds System──Studies On The Redox Properties Of Bis(Undecatungstometalate) Lanthanates, Weiqing Wang, Xiumei Zhang, Jingfu Liu

Journal of Electrochemistry

The redox properties of Ln(MW₁₁)₂ (M=As, Ti, Ga; Ln=La, Ce, Pr,Nd, Sm, Eu, Gd, Dy) are systematically studied. It has been found that the redox order is La(AsW₁₁)₂ > La(TiW₁₁)₂ >La(GaW₁₁)₂.The reduction process of Ln(MW₁₁)₂ anion has been discussed.

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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Developments Of Fundamental Studies In Modern Electrochemistry──A Lecture For The National Advanced Workshop Of Modern Electrochemistry, Zhaowu Tian, Wenduan Su

Journal of Electrochemistry

This paper is a lecture notes spoken by profesor Tian to the national advanced workshop of modern electrochemistry.

Studies Of In-Situ Raman Spectroscopy On Deprotonation And Degeneration Of Ppy Films, Jinsong Gao, Jing Chen, Yanzhen Chen, Qi Xue, Zhongqun Tian

Journal of Electrochemistry

By combining the in-situ Raman spectroscopic technique with the normal electrochemical measurements, the behavior and structure of PPY films in neutral or basic solutions were studied. The oxidized PPY loses protons on the N atoms of pyrrole rings and is deprotonated in these solutions, resulting the formation of the quinoid structure. It makes the C=C stretching vibration bonds of PPY split. Because this quinoid structure can′t be further oxidized, the PPY becomes more difficult to be oxidized and less reversible with the increasing of pH value of solutions and the degree of deprotonation of PPY. In the strong basic solution …

Catalytic Oxidation Of Methanol On Pt/C-Spe And Ptru/C-Spe Electodes, Aihua Su, Changzhi Li, Gongquan Sun, Ying Zhang, Tianhong Lu

Journal of Electrochemistry

Anode catalysts of methanol oxidation for direct methanol fuel cell, Pt/C and PtRu/C, ere prepared by chemical reduction in this work. The results indicated that the PtRu/C showed higher electrocatalytic activity than that of Pt/C. It was explained by XRD and XPS analyses that the existence of Ru enhanced the catalytic activity for electrochemical oxidation of methanol.

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.

Effect Of Deposition Conditions On The Texture Of Zinc Deposits, Shukai Xu, Fangzu Yang, Shaomin Zhou

Journal of Electrochemistry

In this paper, the effects of additives, complex agents and current densities on thetexture and grain size of the zinc deposits from zincate baths are studied by means of X ray diffraction. The results show that the existence of additive AA-1 causes the preferential orientation of (101) face; when DIE is added alone, the preferential orientation changes to (110) face; with additives both DIE and AA-1, Zn deposits with highly preferential orientation of (110) are obtained in a certain range of current densities, and if complex agents TEA and EDTA are simultaneously existed, fine granular and bright Zn deposits with …

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 …

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. …

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.

Study Of The Modified Electrolytic Manganese Dioxide, Guohui Yuan, Dewei Chu, Rihui Shen, Hongwei Pan, Cuifen Zhang

Journal of Electrochemistry

A modified electrolytic manganese dioside doped with Bi (Bi-EMD)wasprepared and examined by XRD and XPS. It is predominantly γ-mnO₂ and the Bi exists as Bi₂O₃ in the modified material. The content of Bi in Bi-EMDs increased with the increasement of Bi³⁺ concentration in electrolyte, and reached 14.3(wt)% from the bath of 0.008 mol·L^-1 Bi³⁺ used. Some Zn/Bi-EMD prototype batteries of AA size were assembled, and which cycle life tests showedthat the Bi-EMD has better reversibility.

The Composition Structure And Corrosion Resistance Of Al-Mn Alloy Plating, Jiaju Guo, Naiming Guo

Journal of Electrochemistry

The Al-Mn alloy plating was electrodeposition from low temperature molten salts (below 200℃), its chemical composition control, corrosion resistance as well as the relationshipbetween chemical composition and structure were studied. The results indicate that the main effect onchemical composition of Al-Mn alloy plating is Mn ion concentration in molten salts. The Mn contentin the range of 25～40(wt)%, Al-Mn alloy plating has amorphous structure. In 0.5 mol/L H₂SO₄ and NaCl solution ,corrosion resistance of the alloy plating is much better. When the alloy has amorphous structure, corrosion resistance of plating has been remarkably increased.

Study On Properties Of Ti/Sno2+Sb2O3/Pbo2 Anode, Zhenhai Liang, Sen Wang, Yanping Sun, Wenlin Xu

Journal of Electrochemistry

A novel of anode-Ti/SnO₂+Sb₂O₃/PbO₂ was studied by means of SEM, EDS and XRD. The lifetime and kinetic parameters were determined in l mol/L H₂SO₄. The duel barrier modelwas used to interpret the results for the anode. The results show that the anode have better properties of electrochemistry and longer lifetime.

Application Of Electrochemistry In The Dyeing Of Fiber Textile, Bai Tong, Suzhen Gao, Zunze Wang, Jiling Wei

Journal of Electrochemistry

An electrochemical dyeing method of protein fiber-silk is presented, and aexperimental equation relating to the uptake a and trough voltage V is given. It is shown that the lectrochemical dyeing method can remarkably raise the uptake than common mtehod, reduce energyconsumption and cut down environment pollution. This is a new field for the application ofelectrochemistry.

Influence Of O-Phenylenediamine On The Catalysis At Hrp Enzyme Electrode In 1,4-Dioxane, Hong Chen, Hui-Huang Wu

Journal of Electrochemistry

Horseradish peroxidase (HRP) was immobilized by crosslinkage on the glassycarbon electrode to prepare the enzyme electrode, where the reduction of H₂O₂ was studied in 1,4-dioxane media. It was shown that HRP electrode can catalyze the reduction of H₂O₂ without anymedintor, however, as an activator, o-phenylenediamine can promote the bio-catalysis. In thepresence of the activator, the parallel reactions occurred on the enzyme electrode. The workingcondition of the HRP electrode was investigated as the sensors for H₂O₂ and o-phenylenediamine, also the influence of water content in organic phase was discussed on the performance …

Study Of The Action Mechanism Of A New Type Additive Sd-1 On The Electrodepositional Process Of Zinc, Huaqiang Wu, Yiqin Yan, Guangming Ni

Journal of Electrochemistry

The action mechanism of a new type additive SD-1 on the electrodepositionalprocess of zinc is reported.The results showed that the additive SD-1 is not electrochemistry activesubstane in the range of adsorption potential at rotating disk electrode surface. The action of additive SD-1 on the electrodepositional process of zinc is considerated to be fitting in with the diffusion controlmechanism.

Self-Assembled Monolayers: Preparation,Properties And Application, Xiandui Dong, Juntao Lu, Chuansin Cha

Journal of Electrochemistry

Self-assembling technique is a versatile approach to the preparation of monolayersof well-defined composition, structure, thickness and physicochemical properties. Different aspects, such as wettability, adhesion, corrosion, tribology, electrontransfer, protein adsorption, molecular recognition, and applications of SAMs are widely studied. The developments in the last decade arereviewed, with special attention to the electrochemical studies related to electrodes modified with thiol-derivative-based SAMs.

Electrodeposition Of Cobalt And Rare Earth-Cobalt In Urea-Nabr-Kbr Melt, Qiqin Yang, Kairong Qiu, Derong Zhu, Lichang Sa

Journal of Electrochemistry

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Studies Of Cl- On The Electrochemical Oscillation Behaviour Of Electrodeposited Silver Indium Selenide Thin Films By Using Dynamic Impedance And The Condensance Method, Shaoai Xie, Xunnan Deng, Jinkua You

Journal of Electrochemistry

The electrochemical oscillation behaviour of hydrogen peroxide cathodic reductionprocess on the electro deposited silver indium selenide electrode has been studied by using in-situ dynamic impedance and the condensance measurement technique in different supporting electrolytes solutions. The surface composition of AglnSe₂ electrodes (before and after oscillating) were also givenby AES. According to the experimental results, the influence of Cl^- on the mechanism of this electrochemical oscillaton process has been discussed in detail.

Dielectric Relaxation Of Heterogeneous Systems With Planar Structure──Influence Of The Number And The Electric Conductivity Of Constituent Phases On The Relaxation Pattern, Kongshuang Zhao, Tetsuya Hanai

Journal of Electrochemistry

Heterogeneous systems exhibit a marked dielectric relaxation at frequenciesbetween 0.1kHz and 10 MHz. In order to understand the reason for dielectric relaxation and therelation between the dielectric relaxation and the number of interfaces in heterogeneous systems,as anexample of typical heterogeneous systems, film-solution systems are discussed both theoretically andexperimentally from dielectric point of view. In particular, the frequency profiles of the dielectricrelaxation are analyzed in Connection with structure of the sustems and concentration of theconstituent phases. The reason for the relaxation is represented throrgh phenomenologically based onthe M-W mechanism. The feature of dielectric relaxation of these systems leads to the followhgcharacteristics: …

The Oxidation Of Hydrogen Absotbing Alloys And Its Inhibition, Suqin Wang, Baojia Xia, Geping Yin, Pengfei Shi

Journal of Electrochemistry

This paper introduces the method to judge: 1)the possibility of oxidation of themetal hydride electrode in an anode process by cyclic voltammetric curves, 2)the oxidation pattern ofmetal hydride electrode in oxygen atmosphere in various charged states, and 3)the inhibition ofoxidation of hydrogen absorbing alloys by certain surface treatment.

Studies On Advanced Experimental Methods And Instruments In Electrochemistry, Zhonghua Lin, Jin Luo, Zhongqun Tian, Shigang Sun, Changjian Lin, Bingwei Mao, Yong Yang, Huashui Lin

Journal of Electrochemistry

The following recent advances in the experimental methods and home-madeinstruments in electrochemistry by electrochemistry group in Xiamen University are briefly surveyed.