Pt/Au/Fe3O4的制备及其电化学性能

以制得的纳米Fe₃O₄颗粒作为载体,用还原法将还原出的Au与Pt分别负载到Fe₃O₄颗粒表面,制得纳米Pt/Au/Fe₃O₄复合材料。对Pt/Au/Fe₃O₄进行紫外可见光吸收光谱、透射电子显微镜、X射线衍射及光电子能谱等物理表征,结果表明,Au与Pt均匀地沉积到了Fe₃O₄纳米颗粒表面。对纳米Pt/Au/Fe₃O₄复合材料进行循环伏安扫描,当H₂PtCl₆的加入量达到8 mL时,Pt/Au/Fe₃O₄催化性能最佳;正扫电流峰i_p与扫描速率的平方根v^1/2线性相关,Pt/Au/Fe₃O₄催化氧化甲醇的过程受扩散控制;对催化剂进行201次循环伏安扫描,催化剂仍然能保持较好的催化性能且稳定性良好。因此,所合成催化剂Pt/Au/Fe₃O₄是一种具有良好化学稳定性的阳极催化剂材料。

Preparation of Pt/Au/Fe3O4 nanocomposites and their electrocatalytic activities in methanol oxidation

Pt/Au/Fe₃O₄ nanocomposites were prepared by the continuous reduction method, through loading Pt and Au on the surface of nano Fe₃O₄. The Pt/Au/Fe₃O₄ nanocomposites were characterized by UV-vis spectra, transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectrometer (XPS); their electrocatalytic activities in methanol oxidation were investigated. The results indicated that Au and Pt are uniformly deposited on Fe₃O₄ surface. The cyclic voltammograms of Pt/Au/Fe₃O₄ suggests that the best catalytic performance is achieved when the amount of H₂PtCl₆ added is 8 mL. Current peak i_p is proportional to the square root of scanning speed (v^1/2) and the catalytic methanol oxidation process is under the control of diffusion. The Pt/Au/Fe₃O₄ nanocomposites remain high active during the measurements of cyclic voltammograms for 201 times, suggesting that Pt/Au/Fe₃O₄ is a kind of anode catalyst materials with high chemical activity and stability.