转向单位固定分子催化剂:在多孔上支的位点隔离的Ti乙烯聚合催化剂
Michael W McKittrick1, Christopher W Jones
1School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332, USA.
Journal of the American Chemical Society
|March 12, 2004
概括
一种新的图案制造方法在二氧化表面上制造出孤立的有机金属催化剂. 与传统方法相比,这种技术可以提高高达10倍的聚合催化剂活性.
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
- 聚合物化学 聚合物化学
背景情况:
- 固定催化剂在分离和可重复使用方面具有优势.
- 开发局部隔离的催化剂对于理解反应机制和优化性能至关重要.
- 传统方法往往会导致活动减少的聚合催化剂.
研究的目的:
- 报告一项针对位于该位点上隔离的有机金属催化剂在二氧化上的一般模式方法.
- 为了展示该技术与4组聚合催化剂的应用.
- 为了研究模式催化剂的催化活性.
主要方法:
- 开发了一种新的通用模式方法.
- 该技术用于在表面上制备位点隔离的有机金属催化剂.
- 合成和测试了4组聚合催化剂.
主要成果:
- 模式方法成功制备了与现场隔离的有机金属催化剂.
- 通过模式方法合成的催化剂的活性比传统方法增加了10倍.
- 有图案的aminosilica支对其他金属复合物非常通用.
结论:
- 报告的模式方法为创建位点隔离的有机金属催化剂提供了一种一般方法.
- 这种方法显著提高了聚合催化剂的活性.
- 该技术有可能合成各种固定单位有机金属催化剂.
相关概念视频
Heterogeneous Catalysis
Heterogeneous catalysis involves a catalyst in a different phase from the reactants. It is a process where the catalyst and the reactants are in distinct phases, typically solid and gas or liquid.Most heterogeneous catalysts are metals, metal oxides, or acids. The list includes transition metals like iron (Fe), cobalt (Co), nickel (Ni), palladium (Pd), platinum (Pt), chromium (Cr), manganese (Mn), tungsten (W), silver (Ag), and copper (Cu). These metals possess partially vacant d orbitals that...
Ziegler–Natta Chain-Growth Polymerization: Overview
Ziegler–Natta polymerization is another form of addition or chain‐growth polymerization used for synthesizing linear polymers over branched polymers. The catalyst used for polymerization is the Ziegler–Natta catalyst, named after Karl Ziegler and Giulio Natta, who developed it in 1953. This catalyst is an organometallic complex of titanium tetrachloride and triethyl aluminum, with the active form of the catalyst being an alkyl titanium compound. Using the Ziegler–Natta catalyst, high molecular...
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...


