Very small "window of opportunity" for generating CO oxidation-active Au(n) on TiO2.
Very small "window of opportunity" for generating CO oxidation-active Au(n) on TiO2.
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DOI：
10.1039/c4cp00160e
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发表时间：
2014-03
期刊：
影响因子：
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通讯作者：
Xin Tang;John Schneider;A. Dollinger;Yuan Luo;Anke S. Wörz;K. Judai;S. Abbet;Young Dok Kim;G. Ganteför;D. Fairbrother;U. Heiz;Kit H. Bowen;S. Proch
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文献类型：
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作者：
Xin Tang;John Schneider;A. Dollinger;Yuan Luo;Anke S. Wörz;K. Judai;S. Abbet;Young Dok Kim;G. Ganteför;D. Fairbrother;U. Heiz;Kit H. Bowen;S. Proch
最近在多相催化方面的研究，特别是在UHV条件下以及在现实催化环境中的尺寸选择模型系统，已经证明在催化剂设计时有必要考虑原子的确切数量。如果贵金属，特别是金的量对于实际反应如CO氧化要减少，这是极其重要的。在这里，它表明，在TiO 2上只有Au 6和Au 7簇是活跃的CO氧化，这适用于单晶，薄膜，和二氧化钛簇沉积在HOPG。采用选择尺寸的团簇沉积和TPD方法研究了Aun/TiO_2体系的CO氧化活性，并与Lee等人最近报道的结果进行了比较，得到了一个一致的结果，即只有两个物种具有“活性”。研究的Aun/（TiO 2）93/HOPG复合材料的效率归因于碳辅助的氧溢出从金到载体颗粒和跨越晶界。
Recent research in heterogeneous catalysis, especially on size-selected model systems under UHV conditions and also in realistic catalytic environments, has proved that it is necessary to think in terms of the exact number of atoms when it comes to catalyst design. This is of utmost importance if the amount of noble metal, gold in particular, is to be reduced for practical reactions like CO oxidation. Here it is shown that on TiO2 only Au6 and Au7 clusters are active for CO oxidation which holds for the single crystal, thin films, and titania clusters deposited on HOPG. Size-selected cluster deposition and TPD methods have been employed to investigate the CO oxidation activity of Aun/TiO2 systems which are compared to recent results reported by Lee et al. to form a consistent picture in which only two species can be regarded as "active". The efficiency of investigated Aun/(TiO2)93/HOPG composite materials is attributed to carbon-assisted oxygen spillover from gold to support particles and across grain boundaries.