The Preparation Of Copper-based Multielemrnt Alloy Nanotubes And The Influence Of Alloying Effect On The Catalytic Performance

In order to study the influence of composition and alloying effect on the materials' electrocatalysis properties.In this paper,we had copper nanowires as template,using electrochemical displacement synthesis methods to prepare different kinds of copper-based multicomponent alloy nanotubes and studied of their performance.Firstly,we had chloroplatinic acid as the source of platinum,and copper nanowires as precursor template to prepare different compositions of copper platinum binary alloy nanotubes by controlling the volume of chloroplatinic acid solution.The surface of nanotubes is rough,the diameter,wall thickness and the length of nanotubes are 100-150 nm 15 to 25 nm and 3-5 microns,respectively.Copper and platinum elements distributed uniformly on the wall.We studied the electrochemical performance of materials,the Cu40Pt60 is with the optimal performance.The initial and the half wave potential of oxygen reduction reaction of which are larger than commercial Pt/C by 57 mV and 20 mV,respectively.In the CV curves of methanol oxidation,the ratio of positive and the negative peak current density of Cu40Pt60 is about 1.57 times that of the Pt/C.In order to prove that the effect of alloying will improve the catalytic activity,the oxygen reduction mechanism on the catalyst surface were studied.The electronic structure of Pt 5d orbitals is changed as a result of the Cu atoms embedded,thus weaken interaction between the hydroxyl and alloy surface,improving the rate of catalytic reaction.Secondly,In order to reduce the cost of binary alloy,we use the relatively cheap palladium chloride instead of chloroplatinic acid and prepared different components of CuPd alloy nanotubes by electrochemical displacement synthesis methods.The performance of most catalysts in the process of methanol oxidation are better than commercial Pt/C.The atomic ratio of Cu20Pdg0 is with the optimal performance.In order to further study the effect of alloying effect on the performance,the CuPtPd ternary alloy nanotubes ware prepared on the basis of the binary alloy.In the ternary alloy,metal element uniformly distributed on the nanotube wall and the alloying degree of which reached atomic level.Due to the synergistic effect between metals makes it excellent catalytic activity,the different ingredients of which are better than that of commercial Pt/C.Cu28.5Pt27.2Pd34.3 is with the best catalytic performance,the initial potential and half wave potential are higher than commercial Pt/C by 88 mV and 49 mV,respectively.The dynamic current density of which in catalytic kinetics of oxygen reduction is about 8 times that of commercial Pt/C in acidic system at 0.85 V,In the CV curves of methanol oxidation,the ratio of positive and the negative peak current density of Cu28.5Pt27.2Pd34.3 was about 1.9 times that of commercial Pt/C.Finally,by comparing three different types of alloy catalysts,the rank for the catalytic activity of catalysts sorting as follows:CuPtPd NTs>CuPt NTs>CuPd NTs.The ternary alloy on the performance is better than the binary alloy,and copper platinum alloy is better than that of copper palladium alloy.