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氢钼青铜修饰铂电极对甲醇氧化的电催化作用 总被引:2,自引:0,他引:2
利用循环伏安法研究了氢钼青铜在铂电极上的修饰作用和修饰铂电极在c(H2 SO4 ) =0 5mol/L溶液中对甲醇的催化作用。研究结果表明 :铂电极因钼酸盐的还原和钼青铜的氧化而得到修饰 ,低电位范围内修饰铂电极对甲醇的氧化有催化作用 ,催化氧化电流是未修饰电极上的1 6倍。酸性条件下 ,含高价态钼的钼青铜不稳定 ,会不断溶解对铂失去修饰作用 ,对甲醇的氧化效果与未修饰铂电极上的效果相同 ;而低电位时 ,钼青铜修饰铂电极则相对稳定 相似文献
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利用循环伏安法研究了氢钼青铜在铂电极上的修饰作用和修饰铂电极在c(H2SO4)=0.5mol/L,溶液中对甲醇的催化作用,研究结果表明:铂电极因钼酸盐的还原和钼青铜的氧化而得到修饰,低电位范围内修饰钱电极对甲醇的氧化有催化作用,催化氧化电流是未修饰电极上的1.6倍,酸性条件下,含高价态钼的钼青铜不稳定,会不断溶解对铂失去修饰作用,对甲醇姝氧化效果与未修饰铂电极上的效果相同,而低电位时,钼青铜修饰电极则相对稳定。 相似文献
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甲醇在碳载纳米Pt电极上的电化学研究 总被引:1,自引:0,他引:1
应用循环伏安法制备了nano-Pt/GC修饰电极,优化了铂微粒在电极表面的沉积条件,并用扫描电子显微镜(SEM)和在硫酸中的循环伏安曲线对其进行了表征。结果表明铂微粒较为均匀地分散在玻碳电极表面,粒径约为140nm,电极具有很大的比表面积。循环伏安实验结果表明nano-Pt/GC电极对甲醇电氧化的催化活性明显高于铂片电极,在该修饰电极上甲醇正向扫描和反向扫描时的氧化峰电位分别是0.67V和0.49V,峰电流为61.00mA/cm2和50.50mA/cm2,分别是铂片电极上的3.13倍和3.10倍,有效地提高了金属铂的利用率,铂微粒在电极表面的最佳沉积条件是循环次数为100次和沉积速度为5mV/s。 相似文献
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采用水热法制备了F掺杂的TiO2,将其与碳黑机械混合制成复合载体,采用微波辅助加热乙二醇法制备了载Pt电催化剂。通过X射线衍射(XRD)和扫描电镜(SEM)对F-TiO2进行了表征,结果表明,F掺杂后,TiO2仍然呈锐钛矿结构,形貌呈纳米片层结构。Pt/F-TiO2-C催化剂表现出很好的催化活性和稳定性,循环伏安法和计时电流法的测试结果表明,复合载体中F的加入有利于甲醇的电催化氧化,提高了Pt对甲醇氧化的抗毒化能力,使其质量比活性是商业Pt/C催化剂的1.2倍。 相似文献
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SPAN style="FONT-SIZE: .pt FONT-FAMILY: 宋体 mso-bidi-font-size: .pt mso-bidi-font-family: 宋体 mso-font-kerning: .pt mso-ansi-language: EN-US mso-fareast-language: ZH-CN mso-bidi-language: AR-SA mso-ascii-font-family: Times New Roman">朱婉霞 汪伍洋 李美超 莫卫民 《化工学报》2010,61(Z1):96-100
采用循环伏安法和电化学原位红外光谱技术研究了铂修饰聚吡咯电极(nm-Pt/PPy)对甲醇的电催化氧化反应,结果表明,nm-Pt/PPy对甲醇具有较好的电催化活性,当电位为1000mV时,可清楚地观察到甲醇经电氧化生成了最终产物CO2。但是在电化学氧化过程中仍存在CO的毒化现象,在低电位下,CO分别以桥式和线性方式吸附,随着电位升高,逐渐变为以线性吸附为主。另外,电氧化电位不宜过高,nm-Pt/PPy的电催化活性易因聚吡咯过氧化而降低。 相似文献
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甲醇在聚苯胺修饰铂钼共沉积电极上的催化氧化 总被引:1,自引:0,他引:1
用恒电位法和循环伏安法在铂电极上分别制备了聚苯胺修饰的分散氢钼青铜电极和分散铂电极,以及聚苯胺修饰的不同铂钼比例的铂与氢钼青铜共沉积电极。用循环伏安法研究了制备电极在c(H2SO4)=0.5mol/L水溶液中的电化学行为,以及对c(CH3OH)=0.1 mol/L的催化氧化行为。其中,分散氢钼青铜电极对甲醇无催化氧化的作用,铂与氢钼青铜共沉积电极对甲醇的催化氧化效果优于分散铂电极。铂-氢钼青铜共沉积电极对甲醇氧化的催化能力与共沉积铂钼的比例有关,当制备电极所用的溶液中n(氯铂酸)∶n(钼酸钠)=2∶1时,共沉积电极对甲醇的催化氧化活性最高,此时甲醇在共沉积电极上的氧化峰电流是单纯铂电极的2.632倍。 相似文献
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K.L. Nagashree 《Electrochimica acta》2010,55(8):2629-143
Electrocatalytic activity of the Pt microparticles dispersed into polyindole (PIn) films obtained by electropolymerization on carbon paste electrodes (CPE) towards methanol oxidation in perchloric acid medium has been demonstrated and investigated using cyclic voltammetry, potentiodynamic polarization, chronoamperometry and impedance spectroscopic techniques. The results show that PIn films obtained on these electrodes serve as good host matrices for the dispersion of Pt microparticles and exhibit good catalytic activity towards the electrooxidation of methanol compared to bulk Pt and CPE modified with Pt. The morphology and composition of the modified and unmodified films were obtained using SEM and EDX techniques. The effect of scan rate, amount of Pt and concentration of methanol, on the activity of the electrode has been tested. The effect of alloying Pt with different amounts of Ni was studied and it was found that when the metals are deposited from a solution containing the metal salts in 1:1 ratio the activity towards methanol oxidation was significantly enhanced. 相似文献
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Platinum nanoparticles self-assembled onto chitosan membrane as anode for direct methanol fuel cell 总被引:1,自引:1,他引:0
In this article, incorporation of platinum nanoparticles (PtNPs) into chitosan-coated glassy carbon (GC) electrode for methanol
oxidation is studied. Pt–chitosan nanocomposites are prepared and characterized by UV–vis spectroscopy, X-ray powder diffraction
(XRD), and transmission electron microscopy (TEM). Catalytic activity of GC–PtNPs–chitosan electrode for the electrooxidation
of methanol is studied by cyclic voltammetry and chronoamperometry. The current density and potential of the methanol oxidation
are affected by amount of platinum, methanol, sulfuric acid, and chitosan. The current density of the methanol oxidation at
GC–PtNPs–chitosan electrode is measured in optimized conditions and compared with that obtained at the glassy carbon modified
electrode by Pt with different polymers. 相似文献
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Methanol electro‐oxidation is investigated at graphite electrodes modified with various platinum and nickel nano‐particle deposits using cyclic voltammetry. The modified electrodes are prepared by the simultaneous electrodeposition of metals from their salt solutions using potentiostatic and galvanostatic techniques. They show enhanced catalytic activity towards methanol oxidation in KOH solution. The catalytic activity of platinum nano‐particles is found to be significantly affected by the presence of relatively small amounts of nickel deposits. A comparison is made between the electrocatalytic activity of Pt/C and (Pt‐Ni)/C electrodes. The results show that the methanol electro‐oxidation current increases with an increase in the nickel content. In particular, the highest catalytic activity is achieved for platinum to nickel deposits of 95%:5% (wt.‐%), in other cases the catalytic activity decreases. It is found that Ni enhances the catalytic activity of Pt by increasing the number of active sites, as well as through an electron donation process from Ni to Pt. This process takes place once the nickel hydroxide (Ni(OH)2)/nickel oxy‐hydroxide (NiOOH) transformation begins. The effect of the methanol concentration on the methanol oxidation reaction is investigated. The order of reaction, with respect to methanol, at the modified (Pt‐Ni)/C electrode is found to be 0.5. 相似文献
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Electrocatalytic oxidation of methanol and ethanol at carbon ceramic electrode modified with platinum nanoparticles 总被引:1,自引:0,他引:1
The use of carbon ceramic electrode (CCE) modified with platinum particles was studied for the electrocatalytic oxidation of methanol and ethanol by cyclic voltammetry and chronoamperometry. After preparation of a carbon ceramic as an electrode matrix by sol–gel technique, its surface was potentiostatically coated with Pt nanoparticles at −0.2 V vs. SCE in an aqueous solution of 0.1 M H2SO4 containing 0.002 M H2PtCl6. The electrocatalyst was characterized by XRD, SEM and cyclic voltammetry. The effective parameters on electrocatalytic oxidation of the alcohols, i.e. the amount Pt loadings, medium temperature and working potential limit in anodic direction were investigated and the results were discussed. This modified electrode showed an enhanced current density over the other Pt-modified electrodes making it more attractive for fuel cell applications. 相似文献
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Lei Zhang 《Electrochimica acta》2007,52(24):6969-6975
Polyaniline-β-naphthalenesulfonic acid composite film on platinum electrode surface has been synthesized via the electrochemical polymerization of aniline in the presence of β-naphthalenesulfonic acid (NSA). FT-IR, UV-vis and electrochemical characterization indicate the formation of the doped polyaniline. Further investigations found that the polyaniline (PAN) doped with NSA extended the electroactivity of PAN in neutral and even in alkaline media. The PAN-NSA composite film coated platinum electrodes are shown to be good electrocatalytic surfaces for the oxidation of ascorbic acid (AA) in phosphate buffer solution (PBS) of pH 7.0. The anode peak potential of AA shifts from 0.62 V at bare platinum electrode to 0.34 V at the PAN-NSA composite modified platinum electrode with greatly enhanced current response. A linear calibration graph is obtained over the AA concentration range of 5-60 mM using cyclic voltammetry. The kinetics of the catalytic reaction is investigated using rotating disk electrode (RDE) voltammetry, cyclic voltammetry and chronoamperometry. The results are explained using the theory of electrocatalytic reactions at chemically modified electrodes. The PAN-NSA composite film on the electrode surface shows good reproducibility and stability. 相似文献
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铂微粒修饰聚苯胺膜电极对甲酸电催化氧化的研究 总被引:1,自引:0,他引:1
采用循环伏安法研究Pt盘电极 (Pt)、铂微粒修饰Pt盘电极 [Pt(Pt) ]和Pt微粒修饰聚苯胺膜电极 [PAN(Pt) ]对甲酸电催化氧化行为的影响 ,比较了它们对甲酸电催化氧化的活性 ,发现PAN(Pt)电极对甲酸电催化氧化的表观电流密度为 3 79× 10 2 mA·cm-2 ,分别比Pt、Pt(Pt)和Pt-PDMA/Pt电极约高 2 35、2 5和 6 3倍。峰电位比Pt PDMA/Pt电极约低 0 16V。 相似文献
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Yongling Du Kangle Lv Biquan Su Nuo Zhang Chunming Wang 《Journal of Applied Electrochemistry》2009,39(12):2409-2414
With polystyrene latex spheres self-assembled on indium tin oxide-coated glass electrode as templates, highly ordered macroporous
Pt was prepared by electrochemical deposition. Then, the macroporous Pt was modified by Pd monolayer involving the galvanic
displacement of Cu monolayer formed by under-potential deposition on macroporous Pt. Electrocatalytic properties of the Pd-modified
macroporous Pt electrode for oxygen reduction were investigated by cyclic voltammetry and chronoamperometry in O2-saturated solution containing 0.1 M HClO4. Methanol electro-oxidation on the Pd-modified macroporous Pt surfaces in 0.5 M H2SO4 containing 1 M CH3OH was studied by cyclic voltammetry. The corresponding results showed that Pd-modified macroporous Pt electrode had negative
catalytic activity for methanol oxidation in compared with macroporous Pt. However, Pd-modified macroporous Pt electrode had
positive electrocatalytic activity to O2 reduction. 相似文献
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The oxidation of formic acid was examined by cyclic voltammetry and chronoamperometry in order to determine the rate of catalytic activity (reaction turnover) as a function of surface crystallography on preferentially oriented (electrochemically modified) platinum electrodes. The resulting turnover rates indicated a maximum fourfold current enhancement for an approximately 60% (111)-oriented surface versus a polycrystalline surface, suggesting that preferentially oriented electrodes are of potential practical significance. 相似文献
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Electrochemical oxidation of methanol on carbon supported Pt/Ru gas diffusion electrodes was investigated in a cyclone flow cell at room temperature using chronoamperometry, cyclic voltammetry and electrochemical impedance spectroscopy. The influence of the flow rate was checked. It was proved that the cyclone cell is suitable for the investigation of methanol electrooxidation and provides additional information on the mass transfer limitations in the electrode assembly. Chronoamperometric measurements showed slow, but constant current decay at all investigated potentials. Impedance measurements in water and methanol containing solutions were performed and the experimental data were fitted to an appropriate equivalent circuit. 相似文献