Preparation of Highly Active, Low Au-Loaded, Au/CeO2 Nanoparticle Catalysts That Promote CO Oxidation at Ambient Temperatures
Preparation of Highly Active, Low Au-Loaded, Au/CeO2 Nanoparticle Catalysts That Promote CO Oxidation at Ambient Temperatures
复制标题
常温下促进 CO 氧化的高活性、低 Au 负载量 Au/CeO2 纳米颗粒催化剂的制备
DOI：
10.1021/jp908313t
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发表时间：
2010-01
影响因子：
3.7
通讯作者：
Wang, Xiaojing
中科院分区：
文献类型：
--
作者：
Tang, Changhe;Li, Guangshe;Smith, Richard L., Jr.;Shen, Yuenian;Han, Mingmei;Wang, Xiaojing
本文采用多种溶液化学方法制备了高活性、低Au负载量的CeO2纳米催化剂，并对其在低温CO氧化反应中的应用进行了研究。用X-射线衍射仪、透射电子显微镜、X射线光电子能谱和UV-−-Vis漫反射光谱对纳米CeO_2和Au/CeO_2催化剂的结构进行了表征。CeO2载体的比表面积为120m2/g，颗粒尺寸为9~15 nm。大的比表面积和细小的尺寸使得Au物种在CeO2载体上有很高的分散性。当Au负载量为0.52wt%时，CO在0℃时的转化率为80%，在20℃时转化率为100%，表明该催化剂具有高效的低温氧化作用。Au/CeO2催化剂中的化学物种为Au~(0+)、Au~+和Au~(3+)，其中Au~+是催化剂的主要活性物种。在催化反应中，Au~(3+)可能被还原为Au~+，从而增强了催化剂的催化活性。
In this work, highly active, low Au-loaded CeO2 nanoparticle catalysts were prepared by several solution chemistries and studied for low-temperature CO oxidation applications. Structures of the CeO2 nanoparticles and the resulting Au/CeO2 catalysts were characterized by X-ray diffraction, transmission electron microscope, X-ray photoelectron spectroscopy, and UV−vis diffuse reflectance spectra. The CeO2 support had a surface area of 120 m2/g and had particle sizes that ranged from 9 to 15 nm. The large surface area of the particles and their fine sizes allowed high dispersion of Au species over the CeO2 support. Conversion of CO to CO2 with the catalyst was significant (ca. 80%) at 0 °C and complete (100%) at 20 °C for a Au loading of 0.52 wt %, demonstrating efficient low-temperature oxidation. Chemical species present in the Au/CeO2 catalyst were Au0, Au+, and Au3+, in which Au+ acted as the dominant active species. During the catalytic reactions, Au3+ was probably reduced to Au+, which enhanced the cat...