将易斯基位固定为稳定的乙选择性MOF,使乙烯从三级混合物中单步分离
Xiao-Wen Gu1, Jia-Xin Wang1, Enyu Wu1
1State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China.
Journal of the American Chemical Society
|February 3, 2022
概括
这项研究引入了氨基功能化UiO-67以有效地从气体混合物中净化乙烯 (C2H4). 新型吸附剂在石化工业中表现出优越的选择性和乙烯生产能力.
科学领域:
- 材料科学
- 化学工程
- 分离科学
背景情况:
- 从乙烯 (C2H2),乙 (C2H6) 和乙烯的三元混合物中有效净化对石化工业至关重要.
- 现有的单步吸附分离方法在实现高性能方面面临挑战.
- 需要开发具有定制性能的先进吸附剂,以有效净化C2H4.
研究的目的:
- 设计和合成一种新型吸附剂,以高效地从三元混合物中净化聚合物级乙烯 (C2H4).
- 研究将易斯基点纳入C2H6选择性金属有机框架 (MOF) 的效果,以提高分离性能.
- 评估吸附剂同时捕获乙 (C2H2) 和乙 (C2H6) 的能力,同时允许乙 (C2H4) 通过.
主要方法:
- 通过将氨基群纳入稳定的C2H6选择性MOF来合成氨基功能化的UiO-67 (UiO-67-NH2).
- 使用理论计算和现场红外光谱来了解吸附机制的吸附剂的特征.
- 通过在各种条件下使用三元C2H2/C2H6/C2H4混合物的突破性实验来评估性能.
主要成果:
- 与原始MOF相比,氨基功能化的UiO-67-NH2) 2具有显著增强的C2H2和C2H6吸附能力.
- 在C2H2/C2H4和C2H6/C2H4分离方面实现了基准选择性,超过了之前报告的材料.
- 在突破性实验中在环境条件下显示出0.55 mmol g-1的显著C2H4生产率.
结论:
- 将氨基群纳入UiO-67有效地增强了其C2H2和C2H6吸附,使得C2H4的有效净化成为可能.
- 孔隙封闭和功能性氨基群的协同作用导致与C2H2和C2H6相比C2H4的相互作用更强.
- UiO-67-(NH2) 2 是一个非常有前途的吸附剂,可用于工业级聚合物级乙烯的单步净化.
相关概念视频
02:17Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule
14.8K
If a set of reactants can yield multiple constitutional isomers, but one of the isomers is obtained as the major product, the reaction is said to be regioselective. In such reactions, bond formation or breaking is favored at one reaction site over others.
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
14.8K
02:34Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
8.7K
The rate of acid-catalyzed hydration of alkenes depends on the alkene's structure, as the presence of alkyl substituents at the double bond can significantly influence the rate.
8.7K
02:43E2 Reaction: Stereochemistry and Regiochemistry
12.1K
Elimination reactions of alkyl halides can yield one or more alkenes depending on the specific regiochemical and stereochemical considerations. While the regiochemistry of the reaction governs the location of the double bond in the product, the stereochemical requirements often influence the geometry.
When a substrate with two different β hydrogens undergoes an E2 elimination, the presence of a strong base can yield two regioisomeric alkenes. The more-substituted alkene is the major...
When a substrate with two different β hydrogens undergoes an E2 elimination, the presence of a strong base can yield two regioisomeric alkenes. The more-substituted alkene is the major...
12.1K
02:43E1 Reaction: Stereochemistry and Regiochemistry
10.2K
One of the critical aspects of the E1 reaction mechanism, as also observed in E2, is the regiochemistry, with multiple regioisomers obtained as products. In the example discussed, the presence of water as a weak base favors elimination over substitution to generate two alkenes. Given that alkenes’ stability increases with the number of alkyl groups across the double bond, typically, E1 reactions lead to the Zaitsev product, for this is more substituted and stable than the Hofmann product.
10.2K
01:12Cycloaddition Reactions: MO Requirements for Photochemical Activation
2.2K
Some cycloaddition reactions are activated by heat, while others are initiated by light. For example, a [2 + 2] cycloaddition between two ethylene molecules occurs only in the presence of light. It is photochemically allowed but thermally forbidden.
2.2K
03:08Hydroboration-Oxidation of Alkenes
9.2K
In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
9.2K