Study On The Preparation Of Ni Based Alloy Composited LaNi₅Porous Electrode And Its Performance For Hydrogen Evolution Reaction In Alkali Solution

The hydrogenic energy provide superior combustion heat as well as satisfied thedemand of resource environment and sustainable development while other energycan’t match, so it get a lot attention. As a new type of secondary energy, it also has awide range of applications in MH-Ni batteries, fuel cells and other fields.Electrolysis of water is a common method for preparation of H2, but because ofthe high over-potential and the poor stability of current hydrogen evolution electrodematerials, which lead a large energy consumption and limiting its large scaleproduction. So it has a great significance to improve the catalytic activity andelectricity catalytic stability.In this article, the Ni/（Al+LaNi₅）, Ni-P/（Al+LaNi₅） and Ni-S/（Al+LaNi₅）composite electrodes were made by one-step composite electro-deposition method ina modified Watt’s baths. Then the porous Ni/LaNi₅, Ni-P/（Al+LaNi₅） andNi-S/（Al+LaNi₅） composite electrode were successfully prepared by dissolution Alwith the concentrated alkali solution （6mol/LNaOH）, at60℃.The correspondingmicrographs, element content and structures of porous Ni/LaNi₅composite electrodeswere characterized by SEM, EDS and XRD. Their electrocatalytic characteristics andapparent activation energy for hydrogen evolution reaction （HER） in20wt%NaOHsolution were investigated by cathodic polarization curves （LSV）, cyclicvoltammetric curves （CV） and electrochemical impedance spectroscopy （EIS）. Theresult showed that the porous electrodes have larger specific surface area, lowerinitial precipitation hydrogen potential and lower apparent activation energy.Their stabilization was studied by constant potential with discontinuity electrolysisand constant potential electrolysis, The result of the electrode stabilization wasdiscussed by open-circuit potential （OCP） after constant potential electrolysis andanodic polarization curves.Their stabilization about electrolysis and disconnect electrical were studied byconstant potential electrolysis and constant potential with discontinuity electrolysis, and then the stabilization result of the porous composite electrode was discussed byopen-circuit potential after constant potential electrolysis and anodic polarizationcurves, the result shows that as the hydrogen storage alloy powders （LaNi₅） havestrong adsorption ability of hydrogen, when the electricity was disconnected, theadsorption of hydrogen was released slowly, which protect the electrode, and avoidthe surface to get oxidation. And after the particles were composited into the coating,which would bring positive synergy effect to make the electrodes have more effectiveelectro-catalytic surface.