高度分散的MnxOy/SBA-15的制备及其催化性能

Preparation of Highly Dispersed Mn_xO_y/SBA-15 and Its Catalytic Properties

采用溶液浸渍法将乙酰丙酮锰或硝酸锰的糠醇溶液分别灌注到SBA-15的孔道内,一定条件下将糠醇碳化后再将碳烧除,即可得到高度分散的MnxOy/SBA-15复合催化剂.用X射线衍射、透射电镜和N2吸附-脱附等手段对样品进行了表征.结果表明,SBA-15负载MnxOy后,不仅依然保持高度有序的孔道结构、较大比表面积和孔容,而且MnxOy在SBA-15孔道内部高度分散.乙苯的催化氧化反应结果表明,该催化剂尤其是用乙酰丙酮锰做锰源时具有很高的催化活性和选择性.

Manganese oxides supported on SBA-15 （MnxOJSBA-15） were prepared by incipient wetness impregnation of SBA-15 with furfuryl alcohol （FA） solution of manganese （Ⅱ, Ⅲ） acetylacetonate or manganese nitrate followed by removal of the carbon resulted from carbonized FA. All the samples were characterized by X-ray diffraction, N2 adsorption, and transmission electron microscopy. The results show that the supported material MnxOy/SBA-15 maintained high surface area, large pore volume, and uniform pore size, and MnxOy was present as highly dispersed nanoclusters in the well-ordered mesoporous channels of SBA-15. The catalysts, especially those prepared trom manganese acetylacetonate, exhibited high activity and selectivity in the liquid-phase oxidation of ethylbenzene using tert-butyl hydroperoxide as the oxidant.