Mn-Ce-Co复合氧化物催化剂的制备及其催化燃烧氯苯性能研究

Preparation of Mn-Ce-Co composite oxide and its catalytic performance for combustion of chlorobenzene

采用溶胶-凝胶法制备了一系列不同Mn含量的Mn-Ce-Co复合氧化物催化剂,通过X射线衍射(XRD)、比表面积测定(BET)、氢气程序升温还原(H_2-TPR)、X射线光电子能谱(XPS)手段表征了催化剂的物理化学性能,并探讨了Mn含量、焙烧温度对催化剂催化燃烧氯苯性能的影响。结果表明:适量Mn的添加促使Co进入到CeO_2立方萤石结构中形成Mn-Ce-Co-O三元固溶体,增加了催化剂的比表面积和表面活性氧物种的量,使催化剂表面的氧化能力大幅度强化。此外,适宜的焙烧温度使得催化剂向无定形态转变,进一步提高了催化剂的比表面积和活性组分的分散度,从而提高了催化剂的活性。

A series of Mn-Ce-Co composite oxide catalysts with different Mn contents were prepared by sol-gel method. The physicochemical properties of the catalysts were characterized by X-ray diffraction(XRD), Brunauer Emmett Teller(BET), hydrogen temperature programmed reduction(H2-TPR) and X-ray photoelectron spectroscopy(XPS). The effect of Mn content and calcination temperature on the catalytic performance of the catalyst for the combustion of chlorobenzene was investigated. The results show that the addition of proper amount of Mn promotes the entry of Co into the CeO2 cubic fluorite structure to form a Mn-Ce-Co-O ternary solid solution, which increases the specific surface area of the catalyst and the surface active oxygen species, thereby enhancing the oxidizing ability of the catalyst. In addition, a suitable calcination temperature causes the catalyst to change to an amorphous state, further increasing the specific surface area of the catalyst and the dispersion of the active component, thereby increasing the activity of the catalyst.