通过Co-MFU-4l高度选择性异质二烯聚合:通过阴离子交换制备的单位催化剂
Romain J-C Dubey1, Robert J Comito1, Zhenwei Wu2
1Department of Chemistry, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
Journal of the American Chemical Society
|August 8, 2017
概括
一种新的固体催化剂Co-MFU-4l在1,3-丁烯聚合中达到99%以上的立体选择性. 这种金属有机框架催化剂为异质催化提供了高效率和机械洞察力.
科学领域:
- 催化剂
- 聚合物化学
- 材料科学
背景情况:
- 分子催化剂在聚合过程中提供高立体选择性,但对于大规模的聚烯制造通常是不切实际的.
- 不同质的催化剂对于工业应用是可取的,但往往缺乏分子催化剂所提供的精确控制.
研究的目的:
- 开发一种具有高效率和机理性理解的1,3-丁立体选择性聚合的异质催化剂.
- 探索金属有机框架作为先进催化平台的潜力.
主要方法:
- 通过金属有机框架内的离子交换来制备Co-MFU-4l.
- 使用Co-MFU-4l催化剂对1,3-丁进行立体选择性聚合.
- 使用X射线吸收光谱对催化剂和聚合物进行表征,并分析聚合物特性 (多分散性,立体选择性).
- 开发一种可溶性复合物,以模仿MOF催化剂的结构和反应性.
主要成果:
- 在1,3-二烯聚合过程中,Co-MFU-4l表现出异常高的立体选择性 (> 99% 1,4- cis),超过之前的异质催化剂.
- 催化剂表现出结构弹性单位异质催化剂的特征,由低聚合物多散度 (PDI ≈ 2) 和最小液证明.
- 射线吸收光谱提供了MOF内离散的Co ((II) 协调的证据,类似于tris-pyrazolylborate复合物.
- 鉴定出一种可溶性复合物,可以有效模仿Co-MFU-4l的催化行为.
结论:
- Co-MFU-4l代表了对立体选择性聚合物的异质催化的一个重大进步,实现了分子水平的控制.
- 基于MOF的催化剂提供了一个实用且可调节的平台来生产高cis-1,4-polybutadiene.
- 这项研究突显了MOF在催化中的潜力,使机理学研究和新催化系统的设计成为可能.
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