对于CO2的双金属衍生催化结构-辅助乙激活
Zhenhua Xie1,2, Jingguang G Chen1,2
1Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, United States.
Accounts of chemical research
|August 30, 2023
概括
双金属催化剂可以选择性地将二氧化碳 (CO2) 和乙转化为有价值的化学物质. 催化剂结构,特别是金属氧化物接口,决定了有效升级乙的产品选择性.
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:
- 同时升级二氧化碳 (CO2) 和乙提供了从温室气体和页岩气中获取有价值化学物质的途径.
- 控制乙升级中的产品选择性取决于受CO2影响的选择性C-H和C-C键裂变.
- 具有合金或分离的双金属衍生催化剂,为选择性反应创造关键的界面部位 (例如金属/氧化物,氧化物/金属).
研究的目的:
- 研究双金属催化剂结构在选择性CO2辅助乙升级中的作用.
- 为了将催化剂表面结构与C-H和C-C键裂变选择性相关联.
- 为轻激活先进双金属催化剂提供设计原则.
主要方法:
- 在现场同步子表征技术被用来分析反应条件下的催化剂结构.
- 密度函数理论 (DFT) 的计算被用来理解电子特性和反应机制.
- 对各种双金属催化剂进行了实验数据和DFT结果的全面比较.
主要成果:
- 在金属/合金表面上缺乏电子的氧气促进非选择性的C-H/C-C键裂变,产生合成气.
- 在金属氧化物/金属接口处以电子丰富的氧气增强了选择性C-H裂变,有利于乙烯的生产.
- 催化剂表面结构 (合金与反接口) 可以通过金属组合和比率来控制,从而影响选择性.
结论:
- 催化剂接口上的氧物种的电子特性对于控制乙C-H/C-C键裂变选择性至关重要.
- 热力学上有利的双金属结构 (合金,反接口) 与选择性C-C/C-H键裂变相关.
- 这项研究为选择性CO2辅助乙升级和轻激活提供了机制性见解和设计原则.
更多相关视频
相关概念视频
Catalysis
27.0K
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
27.0K
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.3K
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
3.3K
Reduction of Alkenes: Catalytic Hydrogenation
12.2K
Alkenes undergo reduction by the addition of molecular hydrogen to give alkanes. Because the process generally occurs in the presence of a transition-metal catalyst, the reaction is called catalytic hydrogenation.
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
12.2K
Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
7.8K
Introduction
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
7.8K
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
8.5K
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.
8.5K
Reduction of Benzene to Cyclohexane: Catalytic Hydrogenation
4.6K
Unlike the easy catalytic hydrogenation of an alkene double bond, hydrogenation of a benzene double bond under similar reaction conditions does not take place easily. For example, in the reduction of stilbene, the benzene ring remains unaffected while the alkene bond gets reduced. Hydrogenation of an alkene double bond is exothermic and a favorable process. In contrast, to hydrogenate the first unsaturated bond of benzene, an energy input is needed; that is, the process is endothermic. This is...
4.6K


