Thermally stable single-atom platinum-on-ceria catalysts via atom trapping
Thermally stable single-atom platinum-on-ceria catalysts via atom trapping
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DOI：
10.1126/science.aaf8800
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发表时间：
2016-07-08
期刊：
影响因子：
56.9
通讯作者：
Datye, Abhaya K.
中科院分区：
文献类型：
--
作者：
Jones, John;Xiong, Haifeng;Datye, Abhaya K.
基于稀有贵金属单原子的催化剂可以通过提高反应性和选择性而更有效地使用。然而，催化剂载体上的单原子在高温下加热时可以移动并聚集成纳米颗粒。高温对催化剂的性能是不利的，除非这些可移动的原子能够被捕获。我们使用了具有相似表面积但不同暴露表面面的CeO_2粉末。当与铂/氧化铝催化剂混合并在800℃的空气中老化时，铂转移到CeO2中并被捕获。多面体CeO_2和纳米棒比立方体CeO_2更能有效地固定铂。在高温下进行合成可以确保只占据最稳定的结合部位，从而得到耐烧结性、原子分散的催化剂。
Catalysts based on single atoms of scarce precious metals can lead to more efficient use through enhanced reactivity and selectivity. However, single atoms on catalyst supports can be mobile and aggregate into nanoparticles when heated at elevated temperatures. High temperatures are detrimental to catalyst performance unless these mobile atoms can be trapped. We used ceria powders having similar surface areas but different exposed surface facets. When mixed with a platinum/aluminum oxide catalyst and aged in air at 800 degrees C, the platinum transferred to the ceria and was trapped. Polyhedral ceria and nanorods were more effective than ceria cubes at anchoring the platinum. Performing synthesis at high temperatures ensures that only the most stable binding sites are occupied, yielding a sinter-resistant, atomically dispersed catalyst.