La_2O_3助剂对Au/TiO_2催化氧化CO性能的影响  

Effect of La_2O_3 on Catalytic Performance of Au/TiO_2 for CO Oxidation

作　　者：俞俊[1] 吴贵升[2] 毛东森[2] 卢冠忠[1,2] 

机构地区：[1]华东理工大学工业催化研究所,结构可控先进功能材料及其制备教育部重点实验室,上海200237 [2]上海应用技术学院化学工程系应用催化研究所,上海200235

出　　处：《物理化学学报》2008年第10期1751-1755,共5页Acta Physico-Chimica Sinica

基　　金：国家重点基础研究发展规划项目(973)(2004CB719500);国家自然科学基金(20503005);上海市科委项目(06JC14095);上海市教委科研项目(06OZ010);上海市重点学科建设项目(p1501)资助

摘　　要：采用溶胶-凝胶法制备了TiO2以及La2O3-TiO2载体,再用沉积沉淀法制备Au/TiO2和Au/La2O3-TiO2催化剂,并对催化剂的CO氧化反应活性进行测试.结果表明,La2O3助剂可以显著提高催化剂催化氧化CO的活性.X射线衍射(XRD)、程序升温脱附(TPD)、N2吸附-脱附(BET)表征结果表明,La2O3助剂不仅提高了催化剂比表面积,抑制了TiO2晶粒尺寸的长大,并且增强了TiO2的晶格应变,在O2气氛吸附过程中主要在TiO2表面形成O-物种.原位傅立叶变换红外(FT-IR)结果进一步表明,La的掺杂不仅提高了吸附在Au活性位CO的氧化速率,还使TiO2表面形成第二种活性位,从而显著提高了催化活性.Pure TiO2 and La-doped TiO2 were prepared by the sol-gel method. Au was supported on TiO2 by the deposition-precipitation （DP） method, and its catalytic activity for CO oxidation was tested. The results showed that doping La in Au/TiO2 could improve its catalytic activity obviously for CO oxidation. The analyses of X-ray diffraction （XRD）, temperature-programmed desorption （TPD）, and Brunauer-Emmett-Teller （BET） surface area further showed that the presence of La in TiO2 not only increased its surface area and restrained the growth of TiO2 crystallites, but could also enhance the microstrain of TiO2. In terms of O2-TPD, a new adsorbed species O- appeared on the surface of La-doped TiO2. The results of in-situ Fourier transform-infrared （FT-IR） spectroscopy illustrated that the high activity of Au/La2O3-TiO2 was attributed to the presence of La promoting the reactivity of CO adsorbed on the Au site and the formation of the second active site on the surface of TiO2.

关 键 词：Au/La2O3-TiO2 CO催化氧化 TPD FT-IR 

分 类 号：O643.32[理学—物理化学]