Maximum Noble-Metal Efficiency in Catalytic Materials: Atomically Dispersed Surface Platinum
Maximum Noble-Metal Efficiency in Catalytic Materials: Atomically Dispersed Surface Platinum
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DOI：
10.1002/anie.201402342
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发表时间：
2014-09-22
影响因子：
16.6
通讯作者：
Neyman, Konstantin M.
中科院分区：
文献类型：
--
作者：
Bruix, Albert;Lykhach, Yaroslava;Neyman, Konstantin M.
铂是催化剂中用途最广的元素，但它很稀有，而且价格昂贵，限制了它的大规模应用，例如在燃料电池技术中。尽管如此，传统的催化剂仅使用一小部分Pt含量，即位于催化剂表面的那些原子。为了使贵金属效率最大化，贵金属应该以原子形式分散，并且仅位于材料的最外表面层内。这种原子分散的Pt表面物质确实可以以非常高的稳定性制备。使用DFT计算，我们确定了一个特定的结构元素，二氧化铈的“nanopocket”，它结合Pt 2+如此强烈，它经受住烧结和体扩散。在模型催化剂，我们实验证实了理论预测的稳定性，并在真实的Pt-CeO 2纳米复合材料显示高铂效率的燃料电池催化，我们也确定这些锚定网站。
Platinum is the most versatile element in catalysis, but it is rare and its high price limits large-scale applications, for example in fuel-cell technology. Still, conventional catalysts use only a small fraction of the Pt content, that is, those atoms located at the catalyst's surface. To maximize the noble-metal efficiency, the precious metal should be atomically dispersed and exclusively located within the outermost surface layer of the material. Such atomically dispersed Pt surface species can indeed be prepared with exceptionally high stability. Using DFT calculations we identify a specific structural element, a ceria "nanopocket", which binds Pt2+ so strongly that it withstands sintering and bulk diffusion. On model catalysts we experimentally confirm the theoretically predicted stability, and on real Pt-CeO2 nanocomposites showing high Pt efficiency in fuel-cell catalysis we also identify these anchoring sites.