Morphology effects of nanoscale ceria on the activity of Au/CeO2 catalysts for low-temperature CO oxidation
Morphology effects of nanoscale ceria on the activity of Au/CeO2 catalysts for low-temperature CO oxidation
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纳米二氧化铈的形貌对Au/CeO2催化剂低温CO氧化活性的影响
DOI：
10.1016/j.apcatb.2009.03.015
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发表时间：
2009-07-25
影响因子：
22.1
通讯作者：
Cao, Yong
中科院分区：
文献类型：
--
作者：
Huang, Xin-Song;Sun, Hao;Cao, Yong
研究了沉积在一维CeO 2（1-D）纳米棒和CeO 2纳米颗粒上的Au纳米团簇在室温CO氧化反应中的催化性能。动力学数据表明，以CeO 2纳米棒为载体的Au催化剂的催化活性比以CeO 2纳米颗粒为载体的催化活性有明显的提高。在278 K下，Au/CeO 2纳米棒（Au-CR）催化剂的比速率和表观活化能分别为4.02 mol（CO）g（Au）（-1）h（-1）和15.9 kJ mol（-1），而Au/CeO 2纳米颗粒（Au-CP）催化剂的比速率和表观活化能分别为0.15 mol（CO）g（Au）（-1）h（-1）和28.4 kJ mol（-1），分别通过X射线衍射（XRD）、透射电子显微镜（TEM）、氢程序升温还原（H-2-TPR）、X射线光电子能谱（XPS）、漫反射紫外-可见光谱（DR UV-Vis）和原位漫反射傅里叶变换红外光谱（DRIFTS）的CO吸附揭示了主要暴露的{1 0 0}/{1 1 0}-二氧化铈纳米棒的表面结构对金纳米团簇的固定和分散有很大的优势，这反过来又导致Au-CeO 2表面具有更高的还原性和CO氧化活性。它也被证实，所产生的强金属支持相互作用（SMSI），金纳米团簇的存在下，CeO 2衬底的电子状态有很强的影响。(C)2009 Elsevier B. V.保留所有权利。
Catalytic properties of Au nanoclusters deposited on a one-dimensional CeO2 (1-D) nanorod and CeO2-nanoparticles have been investigated during CO oxidation at ambient temperatures. The kinetic data showed that the activity of Au catalysts could be remarkably improved by using CeO2-nanorods as support compared to the CeO2-nanoparticles. The measured specific rate and apparent activation energy (E-a) at 278 K were 4.02 mol(CO) g(Au)(-1) h(-1) and 15.9 kJ mol(-1), respectively, for the Au/CeO2-nanorods (Au-CR) catalyst, while those for the Au/CeO2-nanoparticles (Au-CP) catalyst were 0.15 mol(CO) g(Au)(-1) h(-1) and 28.4 kJ mol(-1), respectively. Characterization by X-ray diffraction (XRD), transmission electron microscopy (TEM), hydrogen temperature-programmed reduction (H-2-TPR), X-ray photoelectron spectroscopy (XPS), diffuse reflectance UV-Vis spectroscopy (DR UV-Vis) and in situ diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) of CO adsorption reveal that the predominantly exposed {1 0 0}/{1 1 0}-dominated surface structures of ceria nanorods show great superiority for anchoring and dispersing of gold nanoclusters, which in turn leads to a higher reducibility and activity of the Au-CeO2 surface for CO oxidation. It is also confirmed that, arising from the strong metal-support interaction (SMSI), the presence of gold nanoclusters has a strong influence on the electronic state of the CeO2 substrates. (C) 2009 Elsevier B.V. All rights reserved.