A stable copper(hydr)oxide-modified electrode was prepared in 0.5 mol/L NaOH solution by cyclic voltammetry in the range of -250 to 1 000 mV.It can be used for electrochemical studies in the range of -250 to 1000 mV w...A stable copper(hydr)oxide-modified electrode was prepared in 0.5 mol/L NaOH solution by cyclic voltammetry in the range of -250 to 1 000 mV.It can be used for electrochemical studies in the range of -250 to 1000 mV without interfering peaks because there is no oxidation of copper.During an anodic potential sweep,the electro-oxidation of saccharose on Cu occurred by the formation of CuⅢ and this reaction also occurred in the early stages of the reversed cycle until it is stopped by the negative potentials.A mechanism based on the electro-chemical generation of CuⅢ active sites and their subsequent consumption by saccharose was proposed,and the rate law and kinetic parameters were obtained.The charge transfer resistance from theoretical and impedance studies was used to verify the mechanism.Under chronoamperometry regimes,the reaction followed Cottrellian behavior.The transfer of up to 21 electrons was observed in further investigations of the electro-oxidation of saccharose on a(hydr)oxide Cu rotating disk electrode.展开更多
The electrocatalytic oxidation of methanol was studied over Ni, Co and Cu binary or ternary alloys on graphite electrodes in a NaOH solution （0.1 mol/L）. The catalysts were prepared by cycling the graphite electrode...The electrocatalytic oxidation of methanol was studied over Ni, Co and Cu binary or ternary alloys on graphite electrodes in a NaOH solution （0.1 mol/L）. The catalysts were prepared by cycling the graphite electrode in solutions containing Ni, Cu and Co ions at cathodic potentials. The synergistic effects and catalytic activity of the modified electrodes were investigated by cyclic voltammetry （CV）, chronoamperometry CCA） and electrochemical impedance spectroscopy （EIS）. It was found that, in the presence of methanol, the modified Ni-based ternary alloy electrode （G/NiCuCo） exhibited a significantly higher response for methanol oxidation compared to the other samples. The anodic peak currents showed a linear dependency on the square root of the scan rate, which is a characteristic of a diffusion controlled process. During CA studies, the reaction exhibited Cottrellin behavior and the diffusion coefficient of methanol was determined to be 6.25× 10-6 cm2/s and the catalytic rate constant, K, for methanol oxidation was found to be 40×107 cm3/Cmol.s）. EIS was used to investigate the catalytic oxidation of methanol on the surface of the modified electrode.展开更多
文摘A stable copper(hydr)oxide-modified electrode was prepared in 0.5 mol/L NaOH solution by cyclic voltammetry in the range of -250 to 1 000 mV.It can be used for electrochemical studies in the range of -250 to 1000 mV without interfering peaks because there is no oxidation of copper.During an anodic potential sweep,the electro-oxidation of saccharose on Cu occurred by the formation of CuⅢ and this reaction also occurred in the early stages of the reversed cycle until it is stopped by the negative potentials.A mechanism based on the electro-chemical generation of CuⅢ active sites and their subsequent consumption by saccharose was proposed,and the rate law and kinetic parameters were obtained.The charge transfer resistance from theoretical and impedance studies was used to verify the mechanism.Under chronoamperometry regimes,the reaction followed Cottrellian behavior.The transfer of up to 21 electrons was observed in further investigations of the electro-oxidation of saccharose on a(hydr)oxide Cu rotating disk electrode.
基金provided by K.N.Toosi University of Technology Research Council to conduct this research
文摘The electrocatalytic oxidation of methanol was studied over Ni, Co and Cu binary or ternary alloys on graphite electrodes in a NaOH solution （0.1 mol/L）. The catalysts were prepared by cycling the graphite electrode in solutions containing Ni, Cu and Co ions at cathodic potentials. The synergistic effects and catalytic activity of the modified electrodes were investigated by cyclic voltammetry （CV）, chronoamperometry CCA） and electrochemical impedance spectroscopy （EIS）. It was found that, in the presence of methanol, the modified Ni-based ternary alloy electrode （G/NiCuCo） exhibited a significantly higher response for methanol oxidation compared to the other samples. The anodic peak currents showed a linear dependency on the square root of the scan rate, which is a characteristic of a diffusion controlled process. During CA studies, the reaction exhibited Cottrellin behavior and the diffusion coefficient of methanol was determined to be 6.25× 10-6 cm2/s and the catalytic rate constant, K, for methanol oxidation was found to be 40×107 cm3/Cmol.s）. EIS was used to investigate the catalytic oxidation of methanol on the surface of the modified electrode.
