Influence of the host oxide of sulfated-titania catalysts on partial oxidation methanol reaction
Influence of the host oxide of sulfated-titania catalysts on partial oxidation methanol reaction
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DOI：
10.1016/j.apcata.2010.07.017
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发表时间：
2010-09
影响因子：
5.5
通讯作者：
Hongying Zhao;S. Bennici;Jianyi Shen;A. Auroux
中科院分区：
文献类型：
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作者：
Hongying Zhao;S. Bennici;Jianyi Shen;A. Auroux
通过共沉淀法制备了一系列硫酸化二元二氧化钛基（MxOy-TiO 2-SO 42 −，Mx=Cr、Mn、Fe、Co或Mo）催化剂，并测试了其甲醇部分氧化性能。采用X射线衍射（XRD）、X射线光电子能谱（XPS）、拉曼光谱、扫描电子显微镜（SEM）和透射电子显微镜（TEM）对样品的结构进行了表征。酸性和氧化还原性能分别采用氨吸附量热法和程序升温还原-质谱联用（TPR-MS）技术进行了研究。XRD和拉曼光谱表征证实，表面Mx物种基本上100%分散在催化剂上。XPS分析结果表明了Mx物种的氧化态。此外，Ti和S物种存在于其完全氧化状态的所有样品。氨吸附量热法的结果表明，氧化铬和氨之间的表面反应。通过TPR-MS研究发现，MxOy主体氧化物的加入不仅增强了样品TiS的氧化还原性能，而且改变了硫酸盐还原过程。MoO 3-TiO 2-SO 42-样品的催化性能最好，活性较高。此外，反应产物的分布进行了检查，同时提供有关的表面酸性和氧化还原性能的信息。
A series of sulfated binary titania-based (MxOy–TiO2–SO42−, Mx=Cr, Mn, Fe, Co or Mo) catalysts were prepared by co-precipitation and tested for partial oxidation of methanol. The structural properties were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The acidic and redox properties were examined using ammonia adsorption calorimetry and temperature-programmed reduction coupled with mass spectrometry (TPR–MS) techniques, respectively. The surface Mxspecies were essentially 100% dispersed on catalysts, as confirmed by XRD and Raman spectroscopy characterization. XPS results indicated the oxidation state of surface Mxspecies. In addition, Ti and S species were present in their fully oxidized states for all the samples. The results of ammonia adsorption calorimetry showed a surface reaction between chromium oxide and ammonia. The addition of MxOyhost oxide not only enhanced the redox properties of sample TiS but also brought changes in the sulfate reduction process, as investigated by TPR–MS. The best catalytic performance was obtained for sample MoO3–TiO2–SO42−with high activity. Furthermore, the distribution of reaction products was examined to provide information about the surface acidity and redox properties simultaneously.