基于兰的催化剂中的动态活性站点进化决定了乙化途径
Yuting Li1,2, Haifeng Qi3, Zihan Zhu1,2
1State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
Angewandte Chemie (International ed. in English)
|June 20, 2025
概括
兰氧化 (LaOCl) 在乙烯化过程中转化为LaCl3,导致过度化. 稳定LaOCl和管理基是选择性聚乙烯 (PVC) 前体合成的关键.
科学领域:
- 催化剂是一种催化剂.
- 材料科学 材料科学 材料科学
- 化学工程是化学工程的重要组成部分.
背景情况:
- 乙的极端化是一种低碳的途径,可产生聚乙烯 (PVC) 前体.
- 乙化中的选择性问题与过度化有关,而氧化 (LaOCl) 是一个有前途的催化剂.
- 在富含的条件下LaOCl的结构行为及其在选择性丧失中的作用尚不清楚.
研究的目的:
- 为了研究LaOCl在乙化过程中的结构动态.
- 阐明LaOCl催化化过程中选择性丧失背后的机制.
- 了解表面基和催化剂结构在控制选择性的作用.
主要方法:
- 集成先进的光谱技术.
- 理论计算的应用.
- 合成和表征支持Al2O3的LaCl3模型催化剂.
主要成果:
- 观察到从LaOCl到LaCl3的连续转化,与产品分布向三乙烯的转变相关.
- 在化过程中形成的表面基团促进了1,2-二乙烯的吸附和随后的过度化.
- 在Al2O3上单层分散的LaCl3表现出大小依赖的性,与界面氧稳定Cl基进行选择性乙转化为1,2-二乙.
- 聚合的LaCl3纳米粒子由于无法稳定Cl基而没有活动.
结论:
- 催化剂结构显著影响兰他催化化中的选择性.
- 稳定转移性LaOClx物种和控制表面基化学是提高选择性的关键.
- 这些发现为设计用于选择性乙化改进的催化剂提供了指导原则.
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