甲醇与碳化合物的动态自催化反应的分子路径
Shanfan Lin1,2, Yuchun Zhi1, Wei Chen3
1National Engineering Laboratory for Methanol to Olefins, Dalian National Laboratory for Clean Energy, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China.
Journal of the American Chemical Society
|July 28, 2021
概括
甲醇与碳化合物 (MTH) 的反应
科学领域:
- 催化剂
- 化学工程
- 材料科学
背景情况:
- 甲醇与碳化合物 (MTH) 的反应对于从甲醇中产生碳化合物至关重要.
- 在HZSM-5等化物上发生的MTH反应的自催化性质是复杂的,在分子层面上尚不完全理解.
- 了解自催化网络是优化MTH流程的关键.
研究的目的:
- 阐明 HZSM-5 焦化物的 MTH 反应中自催化网络的完整分子路径和化学机制.
- 提供动态多米诺级别反应的理论和实验图像.
- 在MTH反应过程中确定活性位点的演变性质.
主要方法:
- 多技术方法结合动力分析,现场DRIFT光谱,2D 13C-13C MAS NMR,电子状态和预测状态密度 (PDOS) 分析.
- 一开始的分子动力学 (AIMD) 模拟用于在皮秒时间尺度上进行追踪和可视化.
- 多尺度分析以捕捉反应网络的动态.
主要成果:
- 自催化是通过二甲基以太 (DME) 与表面甲基物种 (SMS) 的反应开始的,产生初始的烯酸.
- 鉴定了一种超循环,其中包括一个基于olefins的自催化循环和三个交叉催化循环 (olefinic,methylcyclopentenyl (MCP) 和芳香物种).
- 活动部位从质子酸部位动态演变为具有流体性质的超分子中心.
结论:
- 在HZSM-5的MTH中建立了自催化反应网络的综合理论图像.
- 鉴定到的高循环网络显示出自催化和交叉催化过程的复杂相互作用.
- 这种理解对于推进MTH技术中的催化剂设计和过程控制至关重要.
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