CrOx在ZrO2上的分散状态及其CO还原NO性能的研究

利用XRD和BET等物理技术研究了CrOx对ZrO2的抗烧结性能及Cr的分散状态.结果表明,CrOx是良好的ZrO2抗烧结剂,会抑制ZrO2晶型从无定形→四方→单斜的相变过程;CrOx与ZrO2之间的强相互作用还有利于Crox在ZrO2表面的分散.NO的TPD-MS实验表明,NO在CrOx/ZrO2表面存在两种与ZrO2作用强弱不同的吸附态,在程序升温脱附过程中发生了NO的离解反应.NO+CO的反应实验表明,反应过程中存在中间产物N2O,低温有利生成N2O,而高温有利于转化成N2.

Studies of the Dispersion State of CrOx on ZrO2 and NO-CO Reaction on CrOx/ZrO2 Catalyst

The effect of CrOx on resisting nodulizing of ZrO2 and the dispersion state of CrOx have been studied using XRD and BET techniques. The results indicate that CrOx is an effctive antisintering agent for ZrO2, and it also opposes the tetragonal → monoclinic transition. The strong interaction between CrOx and ZrO2 is beneficial to the dispersion of CrOx on ZrO2 surface. The TPD-MS experiments of NO show that there are two types of adsorbed NO species which interact with CrOx/ZrO2 catalyst in differrent strength. Dissociation of NO occurs in the process of temperature programmed desorption. The experiment indicates that N2O is an intermediate of NO-CO reaction. At lower temperature large amount of N2O will be produced while amount of N2 will be larger at higher temperature.