Tailoring a Pt–Ru catalyst for enhanced methanol electro-oxidation
Tailoring a Pt–Ru catalyst for enhanced methanol electro-oxidation
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DOI：
10.1016/j.jpowsour.2005.06.031
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发表时间：
2006-06
影响因子：
9.2
通讯作者：
R. Raman;A. Shukla;A. Gayen;M. S. Hegde;K. Priolkar;P. Sarode;S. Emura
中科院分区：
文献类型：
--
作者：
R. Raman;A. Shukla;A. Gayen;M. S. Hegde;K. Priolkar;P. Sarode;S. Emura
碳载（1：1）铂钌（Pt-Ru/C）合金催化剂已制备内部的亚硫基络合物路线，并已被定制，以实现增强的活性对甲醇的电氧化，通过在不同的温度下在空气中退火。在90°C的固体聚合物电解质直接甲醇燃料电池（SPE-DMFC）中，在250 ~ 300° C的空气中退火30 min的催化剂样品对甲醇的电氧化表现出良好的上级催化活性。采用X射线粉末衍射（XRD）、透射电子显微镜（TEM）、X射线光电子能谱（XPS）、扩展X射线吸收精细结构（EXAFS）和循环伏安法对Pt-Ru/C催化剂进行了表征。结果表明，Pt-Ru/C催化剂在退火过程中，PtPt和PtRu键均增加，而PtO键收缩。这伴随着Ru/Pt金属比的正变化，表明Ru金属从本体催化剂扩散到表面，氧化钌含量增加。这种处理对于提高Pt-Ru催化剂对甲醇氧化的电化学活性似乎是开创性的。
A carbon-supported (1:1) Pt–Ru (Pt–Ru/C) alloy catalyst has been prepared in-house by the sulfito-complex route, and has been tailored to achieve enhanced activity towards methanol electro-oxidation by annealing it at varying temperatures in air. The catalyst samples annealed between 250 and 300°C in air for 30min exhibit superior catalytic activity towards methanol electro-oxidation in a solid-polymer-electrolyte direct methanol fuel cell (SPE-DMFCs) operating at 90°C. Both the as-prepared and annealed Pt–Ru/C catalysts have been characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), extended X-ray absorption fine structure (EXAFS), and cyclic voltammetry. It is conjectured that while annealing the Pt–Ru/C catalysts, both PtPt and PtRu bonds increase whereas the PtO bond shrinks. This is accompanied with a positive variation in Ru/Pt metal ratio suggesting the diffusion of Ru metal from the bulk catalyst to surface with an increase in oxidic ruthenium content. Such a treatment appears seminal for enhancing the electrochemical activity of Pt–Ru catalysts towards methanol oxidation.