铝柱撑蒙脱石负载Au和Pt催化剂的结构特点及其催化氧化CO性质  

Au or Pt Supported on Al Pillared Montmorillonite: Characterization and Catalytic Activity for CO Oxidation

作　　者：叶青[1] 李冬辉[1] 程水源[1] 康天放[1] 王道[1] 

机构地区：[1]北京工业大学环境与能源工程学院,北京100124

出　　处：《北京工业大学学报》2012年第8期1269-1275,共7页Journal of Beijing University of Technology

基　　金：国家自然科学基金资助项目(20777005);北京市自然科学基金资助项目(8082008)

摘　　要：将钙基蒙脱石(Ca-M)钠化改性制得钠化蒙脱石(Na-M),随后用羟基铝离子柱化液对Na-M柱撑改性制得铝柱撑蒙脱石(Al-PILCS),使用沉积-沉淀法和浸渍法2种方法将Au和Pt负载在Al-PILCS上,制得Au/Al-PILCS和Pt/Al-PILCS.通过X射线衍射仪(XRD)、N2-吸附/脱附、透射电镜(TEM)和X射线光电子能谱仪(XPS)等技术对样品进行表征,并测定其对CO的催化活性.XRD和N2-吸附/脱附结果表明,铝柱撑蒙脱石Al-PILCS的比表面积、微孔面积和微孔体积较蒙脱石原矿Ca-M增加较大.对于Au和Pt负载型Al-PILCS催化剂,Pt/Al-PILCS催化活性明显优于Au/Al-PILCS.制备方法对Pt/Al-PILCS的活性影响较小,而对Au/Al-PILCS的催化活性影响较大.分析表明,不同方法制备Au/Al-PILCS催化活性的差别,主要由于Au颗粒大小和Au氧化态的差别.而Au/Al-PILCS和Pt/Al-PILCS之间的活性差别,可能是由于金和铂的粒径大小和反应机理差异.Abstract： To increases cation exchange capacity （CEC）, Ca-montmorillonite is exchanged upon Ca2＋ and Mg2＋ to Na＋ and forms Na-montmorillonite. Al pillared montmorillonite （Al-PILCS） support is prepared by the intercalation of polymerization of aluminum hydroxyl ions （Al-agent） with Na- montmorillonite and then calcined. Platinum and gold is deposited on Al-PILCS by deposition- precipitation （DP） and impregnation. The characterization and catalytic activity of the samples are investigated by X-ray diffraction （XRD）, N2-sorption analysis, transmission electron microscopy （TEM）, X-ray photoelectron spectroscopy （XPS） techniques, and CO oxidation reaction. Results of XRD and N2-desorption/adsorption show that due to pillaring, Al-PILCS in microporous surface area and micropore volume increase distinctively. The influence of the preparation methods on the catalytic activity for CO oxidation is markedly large for Au/Al-PILCS and negligible for Pt/Al-PILCS catalysts. The DP method gives the most active catalysts for both Pt and Au. Pt catalysts prepared by DP show a much greater activity than Au catalysts. Different activities of Au/Al-PILCS and Pt/Al-PILCS may attribute to two reasons： the size of Au and Pt parties, and different reaction mechenismes. XPS techniques verified that the Au species of the samples is only metal Au~ over Au/Al-PILCS-IM and oxidation state Au8＋ and metal Au0 coexist over Au/Al-PILCS-DP.

关 键 词：铝柱撑蒙脱石 AU Pt CO催化氧化 

分 类 号：O643[理学—物理化学]