超越活性位点:调整金属有机框架支持的乙烯二元化催化剂的活性和选择性
Jian Liu1, Jingyun Ye2, Zhanyong Li1
1Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , United States.
Journal of the American Chemical Society
|August 25, 2018
概括
将特定的连接物引入金属有机框架 (MOF) 精确控制乙烯寡合化中的催化剂选择性,有利于所需的C4产品. 这种修改通过量身定制的支持性质来增强异质催化.
科学领域:
- 不同质的催化
- 材料科学
- 有机金属化学
背景情况:
- 金属有机框架 (MOF) 是异质催化剂的多功能支.
- 调整MOF属性对于控制催化活性和选择性至关重要.
- 乙烯寡合化是一个重要的工业过程,在产品选择性方面存在挑战.
研究的目的:
- 修改NU-1000 MOF支持的立体和电子特性.
- 为了研究引入的配体对Ni (II) 催化位点的作用.
- 在乙烯寡合化中实现C4物种的选择性生产.
主要方法:
- 类似于原子层沉积 (ALD) 的过程,将六乙酸 (Facac-) 和乙乙酸 (Acac-) 连接物引入NU-1000.
- 在修改后的MOF支上安装Ni (II) 位.
- 使用改性催化剂的乙烯寡合反应.
- 密度函数理论 (DFT) 的计算以阐明反应机制.
主要成果:
- 未经修改的NU-1000支持的Ni ((II) 站点产生了C4,C6,C8和聚合物产品的混合物.
- 对于C4产品,Ni-Facac-AIM-NU-1000和Ni-Acac-AIM-NU-1000都表现出定量选择性.
- DFT的计算表明,将连接物重新排列为连接增加了C-C合激活障碍.
结论:
- 结构调节支持调节器在控制MOF的异质催化剂活性和选择性方面发挥着至关重要的作用.
- 分子修饰剂的蒸汽相传递使催化剂支的轻松,晶体学定义的修饰成为可能.
- 对MOF支持的基修饰为精确控制催化结果提供了强大的策略.
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