机械化学衍生铁原子在有缺陷的化上,用于稳定的烯生产
Gian Marco Beshara1, Ivan Surin1, Mikhail Agrachev2
1Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich Vladimir-Prelog-Weg 1 8093 Zurich Switzerland jpr@chem.ethz.ch.
概括
在有缺陷的六角化上的铁单原子催化剂通过N2O-ODHP有效地产生烯. 机械化学合成为稳定,选择性碳化合物氧化提供了一个无溶剂的途径.
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:
- 单原子催化剂 (SAC) 在碳化合物氧化中具有很高的选择性.
- 设计有效的SAC需要仔细选择金属主体组合和合成方法.
研究的目的:
- 在缺陷的六角化 (h-BN) 上开发和表征铁单原子催化剂,用于烯生产.
- 研究机械化学激活对SAC合成和N2O介导氧化脱 (N2O-ODHP) 的有效性.
主要方法:
- 机械化学激活使用球磨机在有缺陷的h-BN上合成Fe SAC.
- 使用先进显微镜,电子磁共振,UV-vis和X射线光电谱学的表征.
- 在N2O-ODHP中测试烯生产的催化性能.
主要成果:
- 在6%的气转化中使用Fe SACs在h-BN.上实现了95%的烯选择性.
- 在40小时内证明了稳定的催化剂性能.
- 确定了原子分散的Fe2+和Fe3+物种作为关键活性位点,与产生CO和破裂副产品的纳米粒子催化剂形成鲜明对比.
结论:
- 机械化学激活是一种可行的无溶剂方法,用于合成SACs.
- 缺陷的h-BN上的Fe SAC对于通过N2O-ODHP选择性烯生产非常有效.
- 催化剂的设计可以防止焦化和金属烧结,确保运行稳定性.
相关概念视频
Hydroboration-Oxidation of Alkenes
8.0K
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.
8.0K
Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
17.9K
Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
17.9K
Regioselectivity and Stereochemistry of Hydroboration
8.1K
A significant aspect of hydroboration–oxidation is the regio- and stereochemical outcome of the reaction.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn...
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn...
8.1K
π Molecular Orbitals of 1,3-Butadiene
8.8K
Conjugated dienes have lower heats of hydrogenation than cumulated and isolated dienes, making them more stable. The enhanced stabilization of conjugated systems can be understood from their π molecular orbitals.
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...
8.8K
Radical Substitution: Allylic Bromination
5.0K
In organic synthesis, the formation of products can be altered by changing the reaction conditions. For example, a dibromo addition product is formed when propene is treated with bromine at room temperature. In contrast, propene undergoes allylic substitution in non-polar solvents at high temperatures to give 3-bromopropene. In order to avoid the addition reaction, the bromine concentration must be kept as low as possible throughout the reaction. This can be achieved using N-bromosuccinimide...
5.0K


