The Mg0.9Ti0.1Ni1?xPdx (x= 0, 0.05, 0.1, 0.15) hydrogen storage electrode alloys were prepared by mechanical alloying. The main phases of the alloys were determined as amorphous by X-ray diffraction(XRD). The corrosio...The Mg0.9Ti0.1Ni1?xPdx (x= 0, 0.05, 0.1, 0.15) hydrogen storage electrode alloys were prepared by mechanical alloying. The main phases of the alloys were determined as amorphous by X-ray diffraction(XRD). The corrosion potentials of the alloys were measured by open circuit potential measurements and the values are ?0.478, ?0.473, ?0.473 and ?0.471 V (vs Hg/HgO electrode) for x=0, 0.05, 0.1, 0.15, respectively. The corrosion currents of the studied alloys were obtained by non-linear fitting of the anodic polarization curve using Bulter-Volmer equation and Levenberg-Marquardt algorithm, which were obtained after different cycles. The initial corrosion currents of the alloys are decreased with the increasing of Pd content. The increasing of Pd content in the alloys inhibits the corrosion rates of the electrode alloys with the progress of cycle number. The electrochemical impedance spectroscopy(EIS) was conducted after open circuit potential of the alloys stabilizing. The impedance data fit well with the theoretical values obtained by the proposed equivalent circuit model. The corrosion resistances and the thickness of surface passive film of the alloys, which were deduced by the analyses of EIS, are enhanced with the increasing of Pd content in the alloys, which are consistent with the results of corrosion rates obtained from anodic polarization measurements.展开更多
The amorphous Mg0.9Ti0.1Ni1?xPdx (x=0, 0.05, 0.1, 0.15) hydrogen storage alloys were prepared by mechanical alloying. The hydrogen desorption kinetics of the electrode alloys were studied by potentiostatic discharge e...The amorphous Mg0.9Ti0.1Ni1?xPdx (x=0, 0.05, 0.1, 0.15) hydrogen storage alloys were prepared by mechanical alloying. The hydrogen desorption kinetics of the electrode alloys were studied by potentiostatic discharge experiments and linear polarization measurements. The experimental results show that the three-dimensional diffusion model dominates the hydrogen desorption process of the electrode alloys. The rate constants of hydrogen desorption reaction, which are obtained from a linear fitting of the model equation, increase with temperature. The activation energies of hydrogen desorption were calculated according to the Arrhenius equation. The calculated values were 46.2, 24.29, 33.4 and 34.95 kJ/mol for x=0, 0.05, 0.1 and 0.15 of Mg0.9Ti0.1Ni1?xPdx (x=0, 0.05, 0.1, 0.15) electrode alloys, respectively. The exchange current densities were determined by the linear polarization experiments. The variation of exchange current densities with Pd content in the alloy electrodes agrees with that of activation energies with Pd content.展开更多
基金Project(20473091) supported by the National Natural Science Foundation of China
文摘The Mg0.9Ti0.1Ni1?xPdx (x= 0, 0.05, 0.1, 0.15) hydrogen storage electrode alloys were prepared by mechanical alloying. The main phases of the alloys were determined as amorphous by X-ray diffraction(XRD). The corrosion potentials of the alloys were measured by open circuit potential measurements and the values are ?0.478, ?0.473, ?0.473 and ?0.471 V (vs Hg/HgO electrode) for x=0, 0.05, 0.1, 0.15, respectively. The corrosion currents of the studied alloys were obtained by non-linear fitting of the anodic polarization curve using Bulter-Volmer equation and Levenberg-Marquardt algorithm, which were obtained after different cycles. The initial corrosion currents of the alloys are decreased with the increasing of Pd content. The increasing of Pd content in the alloys inhibits the corrosion rates of the electrode alloys with the progress of cycle number. The electrochemical impedance spectroscopy(EIS) was conducted after open circuit potential of the alloys stabilizing. The impedance data fit well with the theoretical values obtained by the proposed equivalent circuit model. The corrosion resistances and the thickness of surface passive film of the alloys, which were deduced by the analyses of EIS, are enhanced with the increasing of Pd content in the alloys, which are consistent with the results of corrosion rates obtained from anodic polarization measurements.
基金Projects(20373072, 20473091) supported by the National Natural Science Foundation of China
文摘The amorphous Mg0.9Ti0.1Ni1?xPdx (x=0, 0.05, 0.1, 0.15) hydrogen storage alloys were prepared by mechanical alloying. The hydrogen desorption kinetics of the electrode alloys were studied by potentiostatic discharge experiments and linear polarization measurements. The experimental results show that the three-dimensional diffusion model dominates the hydrogen desorption process of the electrode alloys. The rate constants of hydrogen desorption reaction, which are obtained from a linear fitting of the model equation, increase with temperature. The activation energies of hydrogen desorption were calculated according to the Arrhenius equation. The calculated values were 46.2, 24.29, 33.4 and 34.95 kJ/mol for x=0, 0.05, 0.1 and 0.15 of Mg0.9Ti0.1Ni1?xPdx (x=0, 0.05, 0.1, 0.15) electrode alloys, respectively. The exchange current densities were determined by the linear polarization experiments. The variation of exchange current densities with Pd content in the alloy electrodes agrees with that of activation energies with Pd content.
