在乙烯氧化过程中对工作中的铜催化剂进行Operando TEM研究
Wenqian Yu1,2, Shengnan Yue1,2, Minghe Yang1,2
1College of Chemistry, Fuzhou University, Fuzhou, China.
Nature communications
|February 27, 2025
概括
在乙烯氧化过程中研究铜催化剂揭示了不同的结构和选择性模式. 操作TEM显示了反应条件下的催化剂状态如何决定乙烯氧化物的形成,挑战了以前的假设.
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.
- 表面化学 表面化学
背景情况:
- 活性催化剂是转移稳定的,表面状态受到气相条件和动力学的影响.
- 了解结构-性能关系需要在运行条件下研究催化剂.
研究的目的:
- 在乙烯氧化过程中研究铜催化剂的结构性能关系.
- 为了阐明反应途径,并在操作条件下识别不同的催化机制.
主要方法:
- 运行传输电子显微镜 (TEM) 用于实时结构观测.
- 在线质谱 (MS) 用于监测反应产物.
- 理论计算以帮助阐明路径.
主要成果:
- 确定了三种不同的温度依赖的模式,具有不同的Cu结构 (Cu2O,Cu0/Cu2O振荡,Cu0).
- 低温:近静态的Cu2O通过氧金属循环路对乙烯氧化物 (EO) 和乙烯 (AcH) 有选择性.
- 中温:动态Cu0/Cu2O振荡模式,激活能量降低.
- 高温:主要是Cu0与单层Cu2O有利于直接EO形成,而Cu0促进燃烧.
结论:
- 催化剂结构和在操作条件下的状态对于乙烯氧化中的选择性至关重要.
- 这些发现挑战了超高真空研究中关于金属铜的环氧化选择性的先前结论.
- 强调需要进行操作研究,以准确地表征催化剂和评估性能.
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