摘要
用ＸＰＳ考察了制备温度，钝化气氛和氢还原活化温度对Ｍｏ２Ｎ催化剂表面的影响。在４００℃，氨可将ＭｏＯ３中的Ｍｏ还原到＋４价；继续升温到７００℃氨还原后，则Ｍｏ２＋成为主要组分。钝化样品的表面存在着来自氨的吸附氮和晶格氮两种不同的形式。而在表面钝化过程中引入的氧则在催化剂表面形成氧化薄层。经高温氢还原后，８０％以上的氧物种可被除去，结合ＴＤＳ、ＸＲＤ和热分析等其它研究结果，对Ｍｏ２Ｎ表面的钝化和活化过程进行了较深入的讨论。
The influence of synthesis temperature,passivated atmosphere and reduction temperature in hydrogen on the surface species of Mo 2N catalysts has been investigated with XPS.It was found that the low valence state Mo species on the catalyst surface rapidly increase with the reaction temperature.The introduced oxygen in the passivated procedure reacts with the catalyst surface to form the thin oxide layer.Nearly 80% of the oxygen species on the catalyst surface can be removed using the reduction treatment in hydrogen at 500℃.The characterization of TPD-MS,XRD,DTA and TG for the passivated and reduced samples are also used to interpretate the XPS results.
基金
中国石化总公司北京石油化工科学研究院资助
