由钯纳米溶胶制备Pd/Ce_(0.5)Zr_(0.5)O_2催化剂及其表征研究  

Supported Pd/Ce_(0.5)Zr_(0.5)O_2 Catalyst Prepared from Colloidal Palladium Nanoparticles

作　　者：卫婷[1] 刘立成[1] 何洪[1] 訾学红[1] 戴洪兴[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：《中国稀土学报》2010年第1期16-21,共6页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(20877006;20833011)资助

摘　　要：采用超声膜扩散还原法制备出金属Pd纳米溶胶,然后从Pd纳米溶胶出发,采用不同方法制备出系列纳米Pd/Ce0.5Zr0.5O2催化剂。采用TEM观察Pd纳米粒子的形貌,采用N2吸/脱附,XRD,TPR和ICP对Pd/Ce0.5Zr0.5O2催化剂进行表征,并考察比较了各催化剂对CO+O2的催化活性差别,结果表明:先制备Pd纳米溶胶,再负载于载体上的方法制得的催化剂金属负载量较低,但是其活性最高,CO在150℃就能完全转化,金属分散度较高,活性Pd物种还原温度低,催化剂的CO低温活性与H2还原温度和金属分散度有关。这种催化剂制备方法为在提高催化剂活性的同时降低贵金属用量提供了可能。The colloidal Pd nanoparticles were synthesized by ultra-assistant membrane diffusion reaction （UAMR） firstly, and then three different methods were adopted to prepare a series of Pd/Ce0.5Zr0.5O2 nanoeatalyst from the prepared Pd nanopartieles. The morphology of precursor Pd nanopartieles was studied by means of transmission electron mieroseopy （TEM）, and the catalysts were characterized by a combination of N2 adsorption/desorption, X-ray diffraction （XRD）, temperature-programmed reduction by H2 （H2-TPR） and inductively coupled plasma-atom emission speetrometer （ICP-AES）. The catalytic behavior of the Pd/Ce0.5Zr0.5O2 samples in the CO oxidation reaction was investigated. It was found that the catalyst prepared by synthesizing Pd nanopartcles and then supported on prepared support Ce0.5 Zr0.5O2 exhibited the lowest metal loading, the best catalytic activity for CO oxidation, and a complete conversion of CO to CO2 could be achieved at 150 ℃. The higher metal dispersion and the Pd species with a low reduction temperature might account for the high activity.

关 键 词：Pd溶胶 纳米催化剂 CO催化氧化 稀土 

分 类 号：O643.3[理学—物理化学]