Preparation And Catalytic Properties Of Pt₃Co Nanowires

Cobalt Platinum alloy nanomaterials were electrodeposited in a three-electrode cell by electrochemical methods in this paper. The cell consists of saturated calomei electrode(SCE) as the reference electrode, Pt gauze as the counter electrode, Ag plate and Anodic Aluminum Oxide(AAO) template separately as the working electrode. The AAO template was plated the silver layer as conductive layer.In Co2+ and [Pt Cl6]2- mixed solution which the concentration did not change, and deposited the nanofilms through the different potential. The atomic ratio of the deposited nanofilms was analysised by XRF. And the content of Co increased with the deposition potential decreased, on the contrary, the content of Pt increased. We synthesized the Pt3 Co alloy at-0.4V.The working electrode was replaced by AAO template, and we also synthesised Pt3 Co nanowires at-0.4V.And then we characterized its morphology and crystal structure through SEM and XRD.The synthesized Pt3 Co nanowires were heat treating under vacuum conditions with different annealing temperature and time. The crystal structure of the preparated nanowires under different annealing conditions were analysised by XRD, and we synthesized the structurally ordered solid solution Pt3 Co at 550℃ through 48 h.Through the catalytic properties of the before and after annealing Pt3 Co which crystal structure were disordered solid solution and ordered solid solution, it was shown that ordered solid solution exhibited the higher ORR catalytic activity in the cathode and the disordered solid solution performed the higher MOR catalytic activity in the anode. Through the crystal structure of both, not only did the Pt3 Co Crystal transition occur, but also the lattice shirked, and Pt-Pt interatomic distance also decreased. It was in favor of oxygen adsorption and dissociation. The CO was easily adsorbed on Pt active sites leading to its toxic effects catalytic activity when methanol oxidation, to oxidize the CO to CO2 and let it away from Pt surface, the OHads was needed. But reduced Pt-Pt interatomic distance is not conducive to the adsorption OHads. So the structurally disordered solid solution Pt3 Co had shown the higher MOR catalytic activity in anode and the structurally ordered solid solution Pt3 Co had shown the higher ORR catalytic activity in cathode in the DMFC.