| In recent years, there are many researches of electrocatalytic oxidation among fuel cell subjects. Among them, many electric catalysis systems relates to noble metal electrode, such as platinum electrode. Nickel and its related compounds which can be widely gained, have catalytic activity for ethanol and other alcohols electrooxidation. In this paper, copper-based nickel series alloy were prepared by electroless plating method, thereafter, the composition, morphology were characterized and analyzed by cyclic voltammetry, chronoamperometry and linear scan, electrochemical impedance spectroscopy. Their electrocatalytic oxidation activities of ethanol in alkaline medium was studied by electrochemical testing technology the main results are as follows:(1) Copper-based nickel electrode (Ni-P alloy electrode) was prepared by electroless plating. SEM and EDS image indicate that, on the copper surface, there are depositions of uniform size nickel metal small spherical particles, and these small spherical particles are connected to each other in a chain structure and has a large surface area. Voltammetric characteristics shown that Ni-P alloy electrode has certain electrical catalytic activity for ethanol oxidation in alkaline solution.(2) Copper-based nickel-cobalt electrode (Ni-Co-P alloy electrode) was prepared by electroless plating. The electrocatalytic activities of Ni-Co-P alloy electrode and Ni-P alloy electrode were compared. SEM and EDS image indicate that the particle morphology of Ni-Co-P alloy electrode are massive spherical, and specific surface area is larger, so that the contact surface area of reaction is larger, metal particles cover the copper substrate completely, display a greater surface area, the surface structure is relatively uniform, the metal particle size is uniform too, particles are spherical, attached closely to the copper substrate surface, they are connected to each other to form a porous network structure, show a huge electrical activity surface area, it is more conducive to the occurrence of catalytic oxidation. Electrochemical test results indicate that Ni-Co-P alloy electrode have more excellent catalytic activity for ethanol oxidation, compared with the Ni-P alloy electrode, the starting potential of ethanol oxidation was ahead of0.11V, the oxidation peak current increased to1.2times. The addition of Co obviously improve catalytic activity for ethanol electrooxidation. Co can generate large amounts of oxygen spore at low potential, the oxidation peak current increased to1.2times. and synergism with Ni, promote the occurrence of oxidation reaction.(3) Copper-based metal tin-nickel electrode (Ni-Sn-P alloy) were prepared by simple electroless plating, it also shows very high catalytic activity on the electrooxidation of ethanol. SEM and EDS image indicate that the copper substrate surface supported many uniform Ni, Sn, P particle, the size of particles is uniform, distributed widely, connected by mutual layered stack, the specific surface area were increased, the catalytic activity is greatly improved, in favor of ethanol adsorption oxidation. The electrochemical testing results prove that Ni-Sn-P alloy electrode and the Ni-P alloy electrode, compared to ethanol, has a higher oxidation rate and lower initial oxidation potential, and lower charge transfer resistance. |
