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为提高燃料电池用贵金属铂催化氧还原反应性能,采用改进的多元醇法制备不同金属比例的碳载铂铁合金催化剂(D-Pt_3Fe/C和D-Pt Fe/C)前驱体.随后通过优化在惰性气体环境中的高温煅烧条件,将结构无序的合金结构转变为结构有序的合金催化剂(O-Pt_3Fe/C和O-Pt Fe/C).利用X射线粉末衍射(XRD)、透射电子显微镜(TEM)、电感耦合等离子体原子发射光谱(ICP-AES)和X射线光电子能谱(XPS)对所制得催化剂进行结构表征.结果发现,所制得催化剂的合金纳米颗粒尺寸分布均一(4~6 nm),且均匀负载于碳载体上.利用循环伏安法(CV)、线性扫描伏安法(LSV)对所制得催化剂进行电化学性能评估.结果表明,O-Pt Fe/C的催化活性高于O-Pt_3Fe/C,其质量活性(271.54 m A·g~(-1)Pt)和比活性(0.73 m A·cm-2Pt)分别是商业JM Pt/C催化剂的4.3倍和7.3倍.两种结构有序铂铁催化剂催化氧还原反应活性均高于商业JM Pt/C催化剂.
In order to improve the catalytic performance of platinum-catalyzed oxygen reduction for fuel cells, a modified polyol method was used to prepare precursors of carbon-supported platinum-iron-alloy catalysts (D-Pt 3 Fe / C and D-Pt Fe / C) with different metal ratios, The structure of the disordered alloy was transformed into the ordered alloy catalysts (O-Pt 3 Fe / C and O-Pt Fe / C) by high temperature calcination in an inert gas atmosphere. X-ray powder diffraction (XRD), transmission electron The catalysts were characterized by TEM, ICP-AES and XPS. The results showed that the size distribution of the prepared catalysts was uniform 4 ~ 6 nm), and uniformly loaded on the carbon support.The electrochemical performance of the obtained catalyst was evaluated by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) .The results showed that the O-PtFe / The catalytic activity of C (271.54 m A · g -1 Pt) and specific activity (0.73 m A · cm-2Pt) were higher than that of O-Pt 3 Fe / C, respectively Times and 7.3 times respectively.The catalytic activity of the two kinds of ordered Pt-Fe catalysts was higher than that of commercial JM Pt / C catalysts.