Preparation Of Palladium Nanowires And Application In Alcohols Electro-oxidation

Nature of the material depends not only on the composition of elements, but also dependent on the structure of matter. When the material composition of the structural units is such small as nanometer scale,it would have shown the conventional superiority. In this article,we prepared the metal Palladium nanowires with highly ordered microstructure, and applied in the direct ethanol fuel cell. Palladium-gold nanowires was prepared by replacement reaction, through the synergy of Palladium-gold nanowires to further improve the catalytic ability. First, anodic alumina template with highly ordered microstructure was prepared by high purity aluminum anodic oxidation, use metal titanium plate electrode as the carrier, the metal palladium nanowires was prepared by electrodeposition and then assembled to the electrode surface. with the good electrocatalytic properties of the nanomaterials, Palladium nanowires and Palladium-gold nanowires was used in direct ethanol fuel cell. while the catalytic ability was further enhanced,this will contribute to the use of the direct ethanol fuel cells, and the mechanism of ethanol oxidation were discussed. Specific study as follows:1, highly ordered anodic aluminum oxide template (AAO) was prepared by anodic oxidation. In this paper,we studied the impact of the oxide voltage, the temperature of the electrolyte, the type of electrolyte and electrolyte concentration to the anodic alumina template. The surface of High-purity aluminum will form a certain structure after anodizing porous. Oxidation voltage is the main factors to the diameter and density of the aluminum oxide template,when the voltage is too high and it will be severe corrosion and the surface of the aluminum will become rough, on the low voltage it will not be oxidized; electrolyte concentration is the main factors to the morphology; oxidation time and current density are the main factors affecting the film thickness; increase the current density can accelerate the speed of formation.2, synthesis palladium nanowires using the template. anodic aluminum oxide template (AAO)was fixed on the metal surface of titanium electrodes, between the titanium electrode surface and the AAO template will formes the cylindrical pore. When the Palladium electrodes immersed in liquid, the liquid will be filled in the cylindrical pore, highly ordered nanowire will be prepared by electrodeposition.3, the catalytic activity of palladium nanowires in alcohols was studied by cyclic voltammetry. Recently material platinum was more usd as electrode materials, but platinum was easy to be poisoned, the peak current decreased rapidly. Research suggests that palladium in the oxidation of alcohols has higher activity than platinum in the alkaline environment. Nanowires has large surface areas, and improves the catalyst utilization, while gaps between the nanowires become the reactants to the electrode and reactant diffusion from the electrode,so it has a higher catalytic activity..4, the synergistic catalytic effect of Palladium-gold nanowires. Cyclic voltammetry studies have shown that the catalytic behavior of gold in the ethanol is stable, and not easy to be poisoned. A further study found that the peak potential of the Palladium-gold nanowires will negative shift in alcohol, and its current density is 5 times on the Palladium-gold nanowires than on the pure palladium nanoparticles, showing excellent catalytic activity. From the peak potential shifted negatively and the oxidation current increases, indicating a synergistic effect with gold and palladium. The scan peak current don't decreases with increasing the number of scanning show that the electrode materials have some anti-drug capabilities. Catalytic capabilities, anti-drug capabilities of palladium gold nanowires indicates a good practical application in the direct ethanol fuel cell.