DMFC阳极催化剂Fe_3O_4@Pt的制备及其催化性能

DMFC Anode Catalyst Fe_3O_4@Pt Particles: Synthesis and Catalytic Performance

采用水热法制得粒径为150~300 nm、分散性良好的Fe_3O_4磁性内核颗粒,经APTES对Fe_3O_4进行氨基化修饰后,用NaBH_4原位还原H_2PtCl_6制得Fe_3O_4@Pt核壳结构的DMFC阳极催化剂,对其进行TEM、XRD、XPS、EDS和催化活性及稳定性表征,结果表明:制得的Fe_3O_4@Pt颗粒表面主要由Pt组成,形成了完整包覆一层Pt的Fe_3O_4@Pt粒子,颗粒粒径为200~300 nm,Fe与Pt的原子比近似为3:1;Fe_3O_4@Pt具有良好的稳定性,在循环100圈后,Fe_3O_4@Pt修饰的玻碳电极在新配制的0.5 mol/L H_2SO_4+1 mol/L CH_3OH溶液中循环第101圈的峰电流密度是第一圈的94.51%;纯Pt的峰电流密度仅为Fe_3O_4@Pt的90.73%,Fe_3O_4和Pt之间存在电荷传递,从而提高了Fe_3O_4@Pt的催化活性。因此Fe_3O_4@Pt有望取代Pt作为DMFC的阳极催化剂。

Fe3O4 magnetic core particles was prepared by hydrothermal method with a particle size of 150–300 nm, which showed good dispersibility. After amination of Fe3O4 particles by APTES, combined with in situ reduction of H2PtCl6 with NaBH4, we obtained Fe3O4@Pt with core-shell structure, and used it as a DMFC anode catalyst. The composition, morphology and structure of Fe3O4@Pt were characterized by transmission electron microscopy （TEM）, X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）, and energy-dispersive X-ray spectroscopy （EDS）. The electrocatalytic activities of Fe3O4@ Pt were also investigated by cyclic voltammetry （CV）. As a result, the surface of Fe3O4@ Pt particles mainly composed of Pt. The particle size of Fe3O4@Pt particles is between 200 nm and 300 nm. Atomic ratio between Fe and Pt is about 3：1. The prepared Fe3O4@Pt particles have a good stability. After 100 cycles, the cycle peak current density of the 101th’ cyclic voltammetry curve of glassy carbon electrode modified by Fe3O4@Pt in fresh 0.5 mol/L H2SO4＋1 mol/L CH3OH aqueous solutions is 94.51% of the first cyclic voltammetry curve. The peak current density of pure Pt is only 90.73% compared with that of Fe3O4@Pt. The charge transfer between Fe3O4 and Pt improves the catalytic activity Fe3O4@Pt. As a result, this work demonstrates the potential of Fe3O4@Pt catalyst to replace Pt as the anode of DMFC in the future.