在现场X射线衍射和固态NMR研究化玛-Al(2) O(3) 与HCF(2) ClCl
P J Chupas1, M F Ciraolo, J C Hanson
1Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400, USA.
Journal of the American Chemical Society
|July 18, 2001
概括
这项研究使用了现场X射线衍射和NMR来追踪胺在化二氧化碳-22变异过程中的结构变化. 一个新的化相形成,类似于alpha-AlF(3),影响催化活性.
科学领域:
- 材料科学 材料科学 材料科学
- 催化剂是一种催化剂.
- 无机化学 无机化学
背景情况:
- 化二氧化碳-22 (CHClF2) 对-的变异是一个关键的工业过程.
- 了解催化剂结构演变对于优化性能至关重要.
研究的目的:
- 为了研究在CHClF2变异过程中玛-的局部结构转换.
- 为了将结构变化与催化活性相关联,并确定活性阶段.
主要方法:
- 在现场X射线衍射 (XRD) 和核磁共振 (NMR) 光谱.
- 气相色谱 (GC) 用于监测反应产品.
- 流细胞用于同时XRD和反应监测.
主要成果:
- 在300°C时,米没有显示任何结构变化,但在360°C时形成了一个新阶段,主导500°C.
- 在300°C时通过NMR检测到化 (AlF3) 的形成,相似的α-AlF3相在400°C时占主导地位.
- 活性催化剂阶段在结构上类似于体alpha-AlF3,其缺陷可能会影响催化行为.
结论:
- 在CHClF2对-的变异过程中形成的催化活性相与α-AlF3.3结构相关.
- 催化剂缺陷影响结构灵活性,并可能解释催化性能的变化.
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