MnOx／TiO2催化剂的表面状态与氧化活性

研究了不同负载量的MnO_2/TiO_2系列催化剂的表面状态及CO氧化活性。结果表明,当MnO_2负载量低于5.7wt％时,MnO_2呈Mn_2O_3相;高于5.7wt％时,MnO_2则为Mn_2O_3+MnO_2混合相。Mn_2O_3由分散态到聚集态的分散阀值为0.028g Mn_2O_3/100mm~2 TiO_2。催化剂氧化活性与其表面状态密切相关。当Mn~(3+)、Mn~(4+)共存时,有利于提高氧化活性。

Surface States and Oxidation Activities of MnO_x TiO_2 Catalysts

The surface states and CO oxidation activities of MnO2/TiO2 catalysts with various loading amount were studied in this paper. The results show that manganese oxide was Mn2O3 when the loading amount of MnO2/TiO2 was Lower than 5. 7 wt% , while the loading amount was more than 5. 7 wt%, MnO2 existed in the form of Mn2O3 and MnO2. The threshold of Mn2O3 from the dispersed states to crystalline phase on TiO2 was 0. 028 g Mn2O3/100 m2. The activities of catalysts were relative to their surface states,and the co-existence of Mn3+ and Mn4+ were contributive to increase the activities.