Preparation of Cobalt Oxide Mesoporous Metallic Oxide-Clay Composites and Their Catalytic Performance in the Oxidation of Benzene

Laponite clays composited with alumina,ceria and zirconia etc. were prepared using polyoxocations or simple metal ions as precursors,and then cobalt oxide was loaded onto them to obtain the catalysts. The results showed that compared with laponite clays, the as-prepared laponite had wide range of pore size distribution and increased pore volume. The pore volumes of laponite clays composited with alumina and ceria were more than 0. 75 cm 3 ·g - 1 . N2 isotherm type was maintained after Co3 O4 loading,however,the N2 adsorption decreased with the increase of Co3 O4 loading,indicating the decrease of pore volume,which was caused by the blockage of metallic oxide / clay composites support. Furthermore,dispersion and catalytic performance of the catalysts were significantly influenced by the composited metallic elements. It was shown that according to the diffraction peak half-width of 311 crystal facet and scherrer equation,when the Co loading was 21. 3% at laponite clays composited with Fe,Zr,Ce,Al,the average sizes of Co3 O4 were 17. 2,16. 0,16. 5 and 18. 0 nm,respectively. Alumina composited clay with 21. 3% Co loading showed high catalytic activity,the complete conversion temperature of benzene was 350℃ . Among metallic oxide / laponite composites,the ZrO composited laponite with 21. 3% Co loading exhibited the best catalytic performance,which could completely convert benzene at 310℃ . (1 ~ 3) . 因 此,如何