摘要
金属蒸气合成(MVS)技术始于六十年代末,现已成为合成无机和金属有机化合物的极其有用的方法.近年来,Klabunde和Ozin等把金属蒸气合成技术应用于制备负载型零价金属催化剂获得成功.因而出现了一种新型的合成高分散金属负载催化剂的方法——溶剂化金属原子分散(SMAD)技术.由SMAD法制备的催化剂称为SMAD催化剂.因为SMAD催化剂与常规法制备的催化剂相比具有某些特殊性质,所以受到人们的关注.目前国外在利用静止式原子反应器制备SMAD催化剂时。
Supported catalysts, Fe/r-Al2O3, Fe/SiO2, Co/r-Al4O3,Co/SiO2, Ni/r-A12O3, Ni/SiO2, were prepared by Solvated Metal Atom Impregnation (SMAI) techniques. Transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy techniques were used to characterize the surface properties of the catalysts. TEM and XRD studies confirm that the average crystallite diameters of Fe, Co and Ni on the supports are below 25A. Both the band shape and the characteristic binding energy of Ni2p3/2 XPS peaks (853.1 and 856.4 eV) and Co2p3/2 XPS peaks (778.5 and 781.0 eV) indicate the main species of nickel and cobalt on SiO2 are Ni0 and Co0. Since the samples were exposed to air during mounting for XPS analysis, partially oxidation of Ni and Co took place.
