逆水气转移由RhVO3,4- (n = 3-7) 聚合离子在变化温度下催化
An Zhao1,2, Qing-Yu Liu1,3, Zi-Yu Li1,3
1State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. shengguihe@iccas.ac.cn.
Dalton transactions (Cambridge, England : 2003)
|April 26, 2024
概括
精确定义的-氧化物集群 (RhxVO<0xE1><0xB5><0xA7>) 在较低温度下有效催化逆水-气转移反应. 一个独特的三明治结构增强了反应剂的激活和产品脱离,以实现高效的催化.
科学领域:
- 不同质的催化剂.
- 表面科学是一门学科.
- 材料化学 材料化学
背景情况:
- 了解接口的活性位点对于设计高效的催化剂至关重要.
- 反向水气转移 (RWGS) 反应对于二氧化碳利用至关重要.
- 金属支相互作用显著影响催化性能.
研究的目的:
- 为了研究RWGS反应的精确定义的RhxVO<0xE1><0xB5><0xA7>−集群的催化活性.
- 阐明基于Rh的催化剂中的结构-活性关系.
- 了解氧化瓦纳支在修改Rh集群特性中的作用.
主要方法:
- 经大小控制的RhxVO<0xE1><0xB5><0xA7>− (n=3-7) 集群的合成和表征.
- 用于催化活动测量的高温离子陷反应器 (298-773 K).
- 量子化学计算以合理化实验观测.
主要成果:
- Rh5−7VO<0xE1><0xB5><0xA7>−集群在较低温度下表现出增强的RWGS活性,与孤立的Rh集群相比.
- 在RhxVO<0xE1><0xB5><0xA7>−集群中观察到依赖大小的催化行为.
- 量子化学计算揭示了一个三明治 [Rh<0xE2><0x82><0x92>ut−Rh<0xE2><0x82><0x92>i<0xE2><0x82><0x99>+-VO<0xE1><0xB5><0xA7>−] 结构,负责有效的反应剂吸附/激活和产品脱附.
结论:
- 氧化瓦纳支以电子方式修改Rh集群,为低温RWGS催化创造活点.
- Rh5−7VO<0xE1><0xB5><0xA7>−中独特的三明治结构是它们卓越的催化性能的关键.
- 这项研究为设计基于金属氧化物相互作用的先进异质催化剂提供了基本的见解.
相关概念视频
01:34Radical Halogenation: Thermodynamics
3.8K
The thermodynamic favorability of a reaction is determined by the change in Gibbs free energy (ΔG). ΔG has two components- enthalpy (ΔH) and entropy (ΔS). The entropy component is negligible for alkane halogenation because the number of reactants and product molecules are equal. In this case, the ΔG is governed only by the enthalpy component. The most crucial factor that determines ΔH is the strength of the bonds. ΔH can be determined by comparing the energy...
3.8K
02:45Acid-Catalyzed Hydration of Alkenes
14.0K
Alkenes react with water in the presence of an acid to form an alcohol. In the absence of acid, hydration of alkenes does not occur at a significant rate, and the acid is not consumed in the reaction. Therefore, alkene hydration is an acid-catalyzed reaction.
14.0K
02:17Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule
14.1K
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...
14.1K
01:16Thermal Sigmatropic Reactions: Overview
2.1K
Sigmatropic rearrangements are a class of pericyclic reactions in which a σ bond migrates from one part of a π system to another. These are intramolecular rearrangements where the total number of σ and π bonds remain unchanged.
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in...
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in...
2.1K
02:28Effect of Temperature Change on Reaction Rate
4.1K
The Arrhenius equation,
4.1K
03:40Hess's Law
45.1K
There are two ways to determine the amount of heat involved in a chemical change: measure it experimentally, or calculate it from other experimentally determined enthalpy changes. Some reactions are difficult, if not impossible, to investigate and make accurate measurements for experimentally. And even when a reaction is not hard to perform or measure, it is convenient to be able to determine the heat involved in a reaction without having to perform an experiment.
45.1K