Methanol oxidation catalysis and substructure of PtRu bimetallic nanoparticles
Methanol oxidation catalysis and substructure of PtRu bimetallic nanoparticles
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DOI：
10.1016/j.apcata.2007.04.018
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发表时间：
2007-07
影响因子：
5.5
通讯作者：
H. Nitani;T. Nakagawa;H. Daimon;Y. Kurobe;T. Ono;Y. Honda;A. Koizumi;S. Seino;T. Yamamoto
中科院分区：
文献类型：
--
作者：
H. Nitani;T. Nakagawa;H. Daimon;Y. Kurobe;T. Ono;Y. Honda;A. Koizumi;S. Seino;T. Yamamoto
采用多元醇还原法合成了直接甲醇燃料电池催化材料PtRu/C。磷的加入对减小PtRu颗粒尺寸和提高其催化活性是有效的。所得催化剂的活性是工业催化剂的6倍。采用X射线吸收精细结构（XAFS）、透射电子显微镜（TEM）、X射线衍射（XRD）和X射线荧光（XRF）对样品进行了分析。这些结果表明，由富Pt核和富Ru壳组成的核-壳结构。通过研究XAFS分析确定的配位数，我们发现催化活性和Pt-Ru原子对发生在颗粒表面上的频率之间存在明显的相关性，这支持了“双功能机制”。
Catalytic material of PtRu nanoparticles supported on carbon (PtRu/C) for direct methanol fuel cells was synthesized by a polyol reduction method. Addition of phosphorus was effective for downsizing PtRu particles and improving their catalytic activity. The activity obtained was six times of that of a commercial catalysis. The samples were analyzed by techniques of X-ray absorption fine structure (XAFS) at Pt LIII-edge and Ru K-edge, transmission electron microscope (TEM), X-ray diffraction (XRD) and X-ray fluorescence (XRF). These results indicated a core–shell structure consisting of a Pt-rich core and Ru-rich shell. By examining coordination numbers determined by XAFS analysis, we found a clear correlation between the catalytic activity and the Pt–Ru atomic pair frequency occurring on the particle surface, which supports the “bi-functional mechanism”.