以TiO2多孔微球为载体的CuO/TiO2催化剂的制备、表征及CO氧化催化性能

利用高分子反相悬浮聚合技术结合溶胶-凝胶法制备了纳米TiO2晶粒组成的多孔微球. 以TiO2多孔微球为载体, 利用浸渍法制备了CuO/TiO2催化剂, 用示差扫描量热法、热重分析、X 射线衍射和X射线光电子能谱(XPS)对TiO2多孔微球和催化剂进行了表征, 并对其进行了CO催化氧化性能的评价. 结果表明, 于500 ℃焙烧的TiO2多孔微球基本为锐钛矿型结构, 其粒径为19.5 nm. XPS结果表明, 催化剂中载体和活性组分存在相互作用, Cu除了以Cu2+的形式存在外, 还以部分Cu+和Cu0的形式存在. CO催化氧化研究结果表明, 催化剂的催化活性与浸渍液的浓度和催化剂的焙烧温度有关. 用0.5 mol/L Cu(NO3)2·3H2O溶液浸渍得到的催化剂和于200 ℃焙烧得到的催化剂具有较好的催化活性.

Preparation, Characterization and CO Oxidation Catalytic Properties of CuO/TiO2 Catalysts Supported on Porous Microspheres Composed of TiO2 Nanocrystals

The porous TiO2 microspheres were prepared by the reversed-phase suspension polymerization and sol-gel method. The CuO/TiO2 catalysts with porous microspheres composed of TiO2 nanocrystals as the support were prepared by impregnation method. The properties of the porous TiO2 microspheres and CuO/TiO2 catalysts were studied by TG-DTA, X-ray diffraction, XPS and ICP. The catalytic properties of the catalysts for CO oxidation were studied via a microreactor-GC system. The results show that the porous microspheres were mainly composed of anatase TiO2 nanocrystals with a size of 19.5 nm. The XPS results indicate that there was interaction between the support and the active component, and Cu mainly existed as Cu2+ with some other form. The catalytic activity of the catalysts depends on the concentration of the impregnation solution and the calcination temperature of the CuO/TiO2 catalysts. The catalyst impregnated in 0.5 mol/L Cu(NO3)2·3H2O had a better catalytic activity. The optimum calcination temperature of the CuO/TiO2 catalysts was 200 ℃.