Efficient removal of formaldehyde by nanosized gold on well-defined CeO₂ nanorods at room temperature.
Efficient removal of formaldehyde by nanosized gold on well-defined CeO₂ nanorods at room temperature.
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DOI：
10.1021/es5019477
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发表时间：
2014-07
影响因子：
11.4
通讯作者：
Quanlong Xu;Wanying Lei;Xinyang Li;X. Qi;Jiaguo Yu;Gang Liu;Jinlong Wang;Pengyi Zhang
中科院分区：
文献类型：
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作者：
Quanlong Xu;Wanying Lei;Xinyang Li;X. Qi;Jiaguo Yu;Gang Liu;Jinlong Wang;Pengyi Zhang
通过沉积 - 沉淀法制备了负载在具有暴露的{110}和{100}晶面的明确的二氧化铈（CeO₂）纳米棒上的金（Au）纳米粒子（NPs），并通过粉末X射线衍射、显微拉曼光谱、X射线光电子能谱、氮吸附 - 脱附、透射电子显微镜、高分辨率透射电子显微镜和高角度环形暗场扫描透射电子显微镜对其进行了表征。发现纳米级和亚纳米级的金粒子在不同金含量（0.01 - 5.4 wt%）的二氧化铈载体上共存。在室温下考察了Au/CeO₂催化剂对甲醛（HCHO）氧化为CO₂和H₂O的催化性能，结果表明其性能依赖于金含量，其中1.8 wt%的Au/CeO₂表现出最佳性能。基于氢气程序升温还原和原位傅里叶变换红外光谱观察的结果，Au/CeO₂催化剂的高活性和稳定性主要归因于具有{110}和{100}晶面的明确的二氧化铈纳米棒，其形成氧空位的能量相对较低。此外，金纳米粒子可诱导Ce - O键减弱，进而促进甲醛氧化。
Gold (Au) nanoparticles (NPs) supported on well-defined ceria (CeO2) nanorods with exposed {110} and {100} facets were prepared by a deposition-precipitation method and characterized by powder X-ray diffraction, micro-Raman spectroscopy, X-ray photoelectron spectroscopy, nitrogen adsorption-desorption, transmission electron microscopy, high-resolution transmission electron microscopy, and high-angle annular dark-field scanning transmission electron microscopy. Both nanometer and subnanometer gold particles were found to coexist on ceria supports with various Au contents (0.01-5.4 wt %). The catalytic performance of Au/CeO2 catalysts was examined for formaldehyde (HCHO) oxidation into CO2 and H2O at room temperature and shown to be Au content dependent, with 1.8 wt % Au/CeO2 displaying the best performance. On the basis of the results from hydrogen temperature-programmed reduction and in situ Fourier transform infrared spectroscopy observations, the high reactivity and stability of Au/CeO2 catalysts is mainly attributed to the well-defined ceria nanorods with {110} and {100} facets which present a relatively low energy for oxygen vacancy formation. Furthermore, gold NPs could induce the weakened Ce-O bond which in turn promotes HCHO oxidation.