| Hydrogen energy is generally appreciated all around the world for its prominentmerits, such as cleanability, high efficiency, renewable ability and so on. It is waterelectrolysis that is the important way to get the vast and inexpensive hydrogen energy.In order to decrease cathode overpotential for reducing energy consumption, it’s ofmomentous significance to research new cathode electrode materials which have lowerhydrogen evolution overpotential and high catalytic activity. This thesis researched thepreparation of foamed nickel molybdenum alloy material of high hydrogen evolutionactivity with a template of polyurethane foam with high specific surface area byelectrodeposition, and designed a small electroplating pilot plant to produce hydrogenevolution electrode material of800×800mm2which was used for industrial electrolysis.The template of polyurethane foam must be made to conduct electricity at first,then thickened by electrodeposition, and then pyrolyzed to remove the template,finally deoxidized to get the foam alloy. The template of polyurethane foam was madeto conduct electricity by chemical nickel plating in this paper. According to thecharacteristics of polyurethane foam, the pretreatment process of polyurethane foamwas studied and determined, and the influence of concentration of NiSO46H2O andNaH2PO2H2O, the pH and temperature of chemical plating solution on the chemicaldeposition rate and quality of clad layer was systematacially studied. The technologyand process of alkaline chemical nickel plating and electroplating nickel molybdenumalloy were also designed and determined.The content of H2PO2-and HPO32-was measured by iodometric method. Thecontent of nickel ions and molybdenum ions was measured by spectrophotometry,and the influence of various factors on the test results was studied whenspectrophotometry was used to measure the content of nickel ions and molybdenumions, and the measuring scheme and steps of spectrophotometry were designed anddetermined.On the basis of laboratory experiments, considering some amplification effects,the small electroplating pilot plant of preparation of foamed nickel molybdenum alloymaterial of800×800mm2was designed. The selection of main equipment wasdetermined, and the design drawings of plating hangers, electroplating tank, doublewash tank, other auxiliary tank and the floor plan of the pilot plant were drawn. Andthe construction of the pilot plant and its pilot debugging were completed. In this pilot plant, seventy pieces of foamed nickel molybdenum alloy electrodematerials were prepared and their properties were studied with areal density,polarization curve and electrolyzer experiment. The experimental results showed thatabout90%of the products achieved the production requirements, and hydrogenevolution overpotential η200of the products was between260mV and300mV whichwas far below the one of foamed nickel electrode(η200=496mV), and exchange currentdensity i0of the products was (8.000±4)×10-3A cm-2which was far beyond the one offoamed nickel electrode(i0=2.7×10-5A cm-2). After intermittent electrolysis of50h byelectrolyzer, average cell voltage of foamed nickel molybdenum alloy electrodeincreased about30mV. After the electrolyzer was dismantled, the hydrogen evolutionoverpotential η200of the foamed nickel molybdenum alloy electrode increased about35mV by the test of polarization curve. The test of SEM and EDS showed that theNi-Mo alloy cladding droped off a little after intermittent electrolysis by electrolyzer,and the mass percentage and atom percentage of Mo decreased by about6.86%and2.41%respectively, which made the hydrogen evolution activity of nickel molybdenumalloy electrode decrease. |
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