Thermal stability of MnOx-CeO2 mixed oxide for soot combustion: influence of Al2O3, TiO2, and ZrO2 carriers
Thermal stability of MnOx-CeO2 mixed oxide for soot combustion: influence of Al2O3, TiO2, and ZrO2 carriers
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用于烟灰燃烧的 MnOx-CeO2 混合氧化物的热稳定性：Al2O3、TiO2 和 ZrO2 载体的影响
DOI：
10.1039/c5ra17328k
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发表时间：
2015
期刊：
影响因子：
3.9
通讯作者：
Lu Hanfeng
中科院分区：
文献类型：
--
作者：
Zhou Ying;Xu Chenjun;Sheng Yeqing;Zhu Qiuliang;Chen Yinfei;Lu Hanfeng
采用柠檬酸溶胶-凝胶法制备了以ZrO2、Al2O3和TiO2为载体的MnOx-CeO2 （Mn/Ce = 0.15/0.85）混合氧化物材料，以防止煤烟燃烧反应中ceo2基氧化物催化剂的烧结。采用XRD、BET、HRTEM、H2-TPR和XPS对材料进行了表征。结果表明，由于TiO2由锐钛矿转变为金红石，在800℃下MnOx-CeO2 /TiO2催化剂快速烧结。而负载在Al2O3和ZrO2上的MnOx-CeO2催化剂表现出较高的热稳定性。在800℃时效10 h后，MnOx-CeO2晶体结构在载体上保持高度分散。特别是在ZrO2载体的作用下，MnOx-CeO2在高温环境下可以很好地维持表面氧的数量和氧化还原性能，从而发挥CeO2和ZrO2的协同作用。催化剂的低温氧化还原性能（200℃~ 400℃）与烟尘燃烧活性吻合较好。
MnOx–CeO2 (Mn/Ce = 0.15/0.85) mixed oxide materials supported on ZrO2, Al2O3, and TiO2 were prepared by citrate sol–gel method to prevent the CeO2-based oxide catalyst from sintering during soot combustion reaction. The materials were characterized using XRD, BET method, HRTEM, H2-TPR, and XPS. Results indicate that the MnOx–CeO2/TiO2 catalyst is rapidly sintered at 800 °C because of the TiO2 phase change from anatase to rutile. By contrast, MnOx–CeO2 catalysts supported on Al2O3 and ZrO2 show high thermal stability. After aging at 800 °C for 10 h, the MnOx–CeO2 crystalline structure remained highly dispersed on the carrier. Particularly with the ZrO2 carrier, the amount of surface oxygen species and redox properties of MnOx–CeO2 can be well-maintained for the synergistic effect of CeO2 and ZrO2 in high temperature environments. Good agreement is found between the low-temperature redox property (200 °C to 400 °C) and the soot combustion activity of the catalysts.