Au/CeO_2-TiO_2表面物种在还原和CO氧化过程中的变化  

Change of the Surface Species on Au/CeO_2-TiO_2 during in the Reduction and CO Oxidation

作　　者：俞俊[1,2] 吴贵升[1] 毛东森[1] 卢冠忠[1,2] 

机构地区：[1]上海应用技术学院应用催化研究所,上海200235 [2]华东理工大学工业催化研究所,上海200237

出　　处：《化学学报》2009年第13期1407-1411,共5页Acta Chimica Sinica

基　　金：国家973计划项目(No2004CB719500);国家自然科学基金(No20503005);上海科委重点项目(No06JC14095)资助项目

摘　　要：采用溶胶-凝胶法制备了CeO2-TiO2载体,再用沉积沉淀法制备了Au/CeO2-TiO2催化剂.利用原位漫反射红外(FT-IR),程序升温还原(TPR)、X射线衍射(XRD)、N2吸附-脱附方法考察了催化剂的结构和表面性能.结果表明,CeO2的存在有效抑制TiO2晶粒的长大,增加TiO2的比表面积和晶格应变,从而增强了Au和载体中TiO2的相互作用,使得催化剂表面的氧化能力显著增强.结合原位CO吸附的FT-IR结果表明,不同温度的还原预处理能有效改变催化剂表面氧物种的组成,并对不同氧物种在CO低温氧化过程中的作用进行了分析.CeO2-TiO2 was prepared by the sol-gel method, and Au was supported on CeO2-TiO2 by the deposition-precipitation （DP） method. The in-situ Fourier transform infrared spectroscopy （FT-IR）, temperature-programmed reduction （TPR）, X-ray diffraction （XRD） and N2 sorption were used to characterize the structure and the surface properties of catalyst. The results show that, the presence of CeO2 in TiO2 not only can increase its surface area and restrain the growth of TiO2 crystallites, but can also enhance the micro-strain of TiO2. Based on these effects, the interaction between gold crystallites and the TiO2 can be enhanced, resulting in a promotion of its oxidation capacity. The in-situ FT-IR spectra of CO adsorbed on the catalyst show that, the surface oxygen species of the catalyst can be changed by a reduction of surface at different temperatures, on which the function of various oxygen species for the CO oxidation was discussed.

关 键 词：Au催化剂 CO氧化 CeO2-TiO2载体 表面物种 

分 类 号：O643.3[理学—物理化学]