Preparation Of Cu-Pt Alloy Nanotubes And Their Electrocatalitic Properties

It is a crucial factor to find efficient electro-catalytic materials forimproving energy conversion efficiency of direct methanol fuel cell andpromoting its commercialization. In this article, platinum was alloyed withcopper to improve the efficiency of oxygen reduction reduction and methanoloxidation.First, the copper nanorods were synthesized and the experimentalconditions was researched, including the concentration of sodium hydroxide,amount of ethylene diamine, hydrazine hydrate and reaction temperaturewhich influence the morphology of the copper nanorods。Definitely, with theincrease of the concentration of sodium hydroxide it will result in a rodmorphology of the copper product. The amount of ethylenediamine andhydrazine hydrate should be controlled at an appropriate value to form acopper rod morphology. At last, the higher reaction temperature will reducethe agglomerate phenomenon of the product.Copper-platinum alloy nanotubes were prepared by a galvanicreplacement reaction between the copper rods and chloroplatinic acid. ThenCu-Pt alloy nanotubes were tested to demonstrate their electrocatalytic activity.The electrocatalitic activity of oxygen reduction reaction can be enchanced by copper compressing lattice constant of Pt. As a result, Cu-Pt alloy structurecan reduce the the overpotential of oxygen reduction reaction and reduce theH₂O₂yield. Moreover, Cu₄₀Pt₆₀exhibits the highest specific mass activity.Methanol electro-oxidation test shows the electrocalitic activity, ability ofresisting CO poison, and stability of Pt can be enchanced by Cu. Definitely,Cu₄₀Pt₆₀shows the highest activity in methanol electroxidation while Cu₇₅Pt₂₅shows best ability for resisting CO poison.At last copper-platinum alloy nanotubes were annealed at differenttemperatures to research the enfluence of heat treatment on the change ofcrystal structure of samples. Experimental results showed that the transitiontemperature of crystal structure reaches up to500℃, and the initialdisordered solid solution structural changed to ordered solid solution of CuPtand Cu₃Pt superlattice.