在甲基酸盐的环氧化过程中,TS-1/球形活性碳复合材料
Adrián Osorio Hernández1, Michael Goepel1, David Poppitz1
1Institute of Chemical Technology, Universität Leipzig Linnéstr. 3 04103 Leipzig Germany michael.goepel@uni-leipzig.de.
RSC advances
|March 6, 2025
概括
用球形活性炭 (SAC) 合成二氧化-1 (TS-1) 提高了催化效率. 这项研究揭示了SAC作为一种支持,控制TS-1分散和孔隙结构,以改善甲基酸盐环氧化中的活性.
科学领域:
- 材料科学 材料科学 材料科学
- 催化剂是一种催化剂.
- 化学工程是化学工程的重要组成部分.
背景情况:
- 酸-1 (TS-1) 是一个关键的催化剂,但它的效率可能是有限的.
- 采用球形活性炭 (SAC) 的TS-1复合材料表现出增强的活性,但底层机制尚不清楚.
研究的目的:
- 为了将TS-1/SAC复合材料的物理化学特性和催化活性相关联.
- 了解SAC在TS-1复合催化中的作用.
- 调查反应剂和产品吸附对催化性能的影响.
主要方法:
- 用不同的TS-1重量分数制备TS-1/SAC复合材料.
- 甲基酸盐的异质催化环氧化,使用水性H2O2.2.
- 脉冲场梯度 (PFG) NMR用于分析催化剂结构和动态.
主要成果:
- 与TS-1母TS-1相比,TS-1/SAC复合材料的Ti位点正常化活性增加了多达七倍.
- SAC充当催化剂支,影响TS-1晶体分散和孔隙排列.
- 有证据表明,反应物和产物分子吸附显著影响了催化活性.
结论:
- TS-1/SAC复合材料的增强催化活性归因于SAC的支持功能,该功能优化了TS-1的分散和孔隙结构.
- 通过SAC对TS-1晶体排列和孔隙空间进行控制,对于提高催化性能至关重要.
- 吸附现象在这些复合材料的整体催化效率中起着至关重要的作用.
相关概念视频
02:57Sharpless Epoxidation
3.7K
The conversion of allylic alcohols into epoxides using the chiral catalyst was discovered by K. Barry Sharpless and is known as Sharpless epoxidation. The use of a chiral catalyst enables the formation of one enantiomer of the product in excess. This chiral catalyst is mainly a chiral complex of titanium tetraisopropoxide and tartrate ester (specific stereoisomer). The stereoisomer used in the chiral catalyst dictates the formation of the enantiomer of the product. In other words, the use of...
3.7K
03:00Preparation of Epoxides
7.4K
Overview
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of...
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of...
7.4K
02:24Acid-Catalyzed Ring-Opening of Epoxides
7.0K
Epoxides that are three-membered ring systems are more reactive than other cyclic and acyclic ethers. The high reactivity of epoxides originates from the strain present in the ring. This ring strain acts as a driving force for epoxides to undergo ring-opening reactions either with halogen acids or weak nucleophiles in the presence of mild acid. The acid catalyst converts the epoxide oxygen, a poor leaving group, into an oxonium ion, a better leaving group, making the reaction feasible. The...
7.0K
01:13Olefin Metathesis Polymerization: Overview
2.0K
Recently, the development of olefin metathesis polymerization advanced the field of polymer synthesis. Simply put, the reorganization of substituents on their double bonds between two olefins in the presence of a catalyst is known as the olefin metathesis reaction. The use of metathesis reaction for polymer synthesis is called olefin metathesis polymerization.
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists...
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists...
2.0K
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
9.7K
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
9.7K
02:04Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
5.5K
Diols are compounds with two hydroxyl groups. In addition to syn dihydroxylation, diols can also be synthesized through the process of anti dihydroxylation. The process involves treating an alkene with a peroxycarboxylic acid to form an epoxide. Epoxides are highly strained three-membered rings with oxygen and two carbons occupying the corners of an equilateral triangle. This step is followed by ring-opening of the epoxide in the presence of an aqueous acid to give a trans diol.
5.5K