在ZSM-5用和修饰的化物中将甲醇转化为烯
Yang Bai1, Xianjun Niu1, Yi-En Du1
1Department of Chemistry and Chemical Engineering, Jinzhong University, Jinzhong 030619, China.
Molecules (Basel, Switzerland)
|July 14, 2023
概括
研究人员研究了ZSM-5催化剂的和修饰,用于甲醇转化为芳香化合物 (MTA). 最佳的和比率显著提高了对烯的选择性和产量,这对于高效的芳香制品生产至关重要.
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
- 化学工程是化学工程的重要组成部分.
背景情况:
- 甲醇转化为芳香化合物 (MTA) 是生产有价值的芳香碳化合物的关键过程.
- ZSM-5热带石是MTA的广泛研究的催化剂,但它的选择性和稳定性可以进一步优化.
- 和修改是已知的策略来调整ZSM-5催化剂的特性.
研究的目的:
- 研究不同源对MTA中ZSM-5催化剂性能的影响.
- 探索和修饰对MTA选择性的联合影响,特别是对对 (PX) 的选择性.
- 优化催化剂成分,以提高MTA中的PX选择性和产量.
主要方法:
- 用各种源 (H3PO4, (NH4) 3PO4, (NH4) 2HPO4) 修改的ZSM-5催化剂的合成和表征.
- 进一步修改ZSM-5的和在不同的负载.
- 评估甲醇到芳 (MTA) 反应中的催化剂性能,重点关注选择性和稳定性.
主要成果:
- 源显著影响PX选择性和催化剂稳定性; (NH4) 2HPO4显示出优异的性能.
- 通过改变ZSM-5孔隙结构和酸性部位,P修改提高了PX的形状选择性.
- Zn-P联合修改的催化剂表现出协同效应,最佳的5% Zn和1% P比率产生了90.1%的PX选择性和59%的PX产量增加.
- 增加的P负荷增强了PX选择性,但降低了整体芳香选择性,而 Zn负荷提高了芳香选择性,但降低了PX选择性.
结论:
- 源的选择对于ZSM-5催化剂在MTA中的性能至关重要.
- (NH4) 2HPO4是增强PX选择性和催化剂稳定性的首选源.
- 与和共同修改提供了一条有前途的途径,可以同时提高MTA中的芳香和素选择性,其中特定的比率是关键.
相关概念视频
01:15α-Bromination of Carboxylic Acids: Hell–Volhard–Zelinski Reaction
3.1K
The method to achieve α-brominated carboxylic acids using a mixture of phosphorus tribromide and bromine is known as the Hell–Volhard–Zelinski reaction. The reaction is catalyzed by phosphorus tribromide, which can be used directly or produced in situ from red phosphorus and bromine. The mechanism comprises PBr3 catalyzed conversion of acid to acid bromide and hydrogen bromide. The acid bromide enolizes to its enol form in the presence of HBr. The nucleophilic enol attacks the...
3.1K
01:33Carboxylic Acids to Methylesters: Alkylation using Diazomethane
2.2K
Carboxylic acids react with diazomethane in an ether solvent via alkylation at the carboxylate oxygen atom to give methyl esters of the corresponding acid with excellent yields.
2.2K
01:10Hydrolysis of Chlorobenzene to Phenol: Dow Process
2.9K
Simple aryl halides do not react with nucleophiles under normal conditions. However, the reaction can proceed under drastic conditions involving high temperatures and high pressure to give the substituted products. For example, chlorobenzene is converted to phenol using aqueous sodium hydroxide at 350 °C under high pressure by the Dow process. The reaction follows an elimination-addition mechanism involving a benzyne intermediate. Here, the chloride ion is...
2.9K
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
10.4K
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.
10.4K
01:27Benzene to Phenol via Cumene: Hock Process
3.4K
The synthesis of phenol from benzene via cumene and cumene hydroperoxide is called the Hock process. First, a Friedel–Crafts alkylation reaction of benzene with propene gives cumene. Then cumene forms cumene hydroperoxide via a radical chain reaction. In the chain initiation step, the benzylic hydrogen is abstracted to give a benzylic radical. In the chain propagation step, the benzylic radical reacts with an oxygen diradical to form a cumene hydroperoxide radical. The cumene...
3.4K
01:19Aldehydes and Ketones to Alkenes: Wittig Reaction Overview
7.9K
The Wittig reaction is the conversion of carbonyl compounds-aldehydes and ketones-to alkenes using phosphorus ylides, or the Wittig reagent. The reaction was pioneered by Prof. Georg Wittig, for which he was awarded the Nobel Prize in Chemistry.
7.9K