Alloys of platinum and early transition metals as oxygen reduction electrocatalysts
Alloys of platinum and early transition metals as oxygen reduction electrocatalysts
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DOI：
10.1038/nchem.367
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发表时间：
2009-10-01
期刊：
影响因子：
21.8
通讯作者：
Norskov, J. K.
中科院分区：
文献类型：
--
作者：
Greeley, J.;Stephens, I. E. L.;Norskov, J. K.
低温聚合物电解质膜燃料电池在移动的应用中的广泛使用将需要显著减少其阴极内所含的昂贵Pt的量，所述Pt驱动氧还原反应（ORR）。虽然在这方面已经取得了进展，但仍然需要通过开发更活跃和更稳定的电催化剂来进一步减少。在这里，我们描述了一组新的ORR电催化剂组成的Pd或Pt合金与早期过渡金属，如Sc或Y。使用密度泛函理论计算将它们鉴定为最稳定的Pt和Pd基二元合金，ORR活性可能优于Pt。电化学测量表明，在0.9- 0.87V范围内，多晶Pt（3）Sc和Pt（3）Y电极的活性相对于纯Pt分别提高了1.5-1.8倍和6-10倍。
The widespread use of low-temperature polymer electrolyte membrane fuel cells for mobile applications will require significant reductions in the amount of expensive Pt contained within their cathodes, which drive the oxygen reduction reaction (ORR). Although progress has been made in this respect, further reductions through the development of more active and stable electrocatalysts are still necessary. Here we describe a new set of ORR electrocatalysts consisting of Pd or Pt alloyed with early transition metals such as Sc or Y. They were identified using density functional theory calculations as being the most stable Pt- and Pd-based binary alloys with ORR activity likely to be better than Pt. Electrochemical measurements show that the activity of polycrystalline Pt(3)Sc and Pt(3)Y electrodes is enhanced relative to pure Pt by a factor of 1.5-1.8 and 6-10, respectively, in the range 0.9-0.87 V.