没有协调不和位点的硫化物催化:化, cis-trans 异构化和 H2 / D2 在 MoS2 和 WS2 上的混杂
Thomas Drescher1, Felix Niefind, Wolfgang Bensch
1Laboratory of Industrial Chemistry, Ruhr University Bochum, P.O. Box 102148, 44780 Bochum, Germany.
Journal of the American Chemical Society
|November 7, 2012
概括
二硫化物 (MoS2) 和二硫化物 (WS2) 催化了硫化物和表面的反应,反驳了要求催化协调不和的理论. 这支持新的理论模型与实验证据.
科学领域:
- 不同质的催化剂.
- 表面科学是一门科学.
- 材料化学 材料化学
背景情况:
- 经典催化理论提出,协调不和对于表面反应至关重要.
- 以前的理论和模型催化剂研究表明了催化剂的替代机制.
- 在真实的催化系统上缺乏实验验证.
研究的目的:
- 在特定的表面条件下实验研究MoS2和WS2的催化活性.
- 在异质催化中挑战协调不和的既定范式.
- 为新兴的催化理论提供经验支持.
主要方法:
- 使用了简单的测试反应:乙烯化,2-丁烯 cis-trans 异构化和 H2/D2 杂乱.
- 采用X射线光电子光谱 (XPS) 来分析表面状态.
- 专注于MoS2和WS2催化剂在没有化学吸收氧气的表面状态.
主要成果:
- MoS2和WS2在和硫化物种的表面上表现出催化活性.
- 这些活性表面的特点是缺少氧气化学吸收.
- XPS分析证实了催化活性位点的硫化物和.
结论:
- 催化可以发生在协调和的表面上,这与经典理论相矛盾.
- 这些发现通过实验验证了通过理论计算和模型研究开发的催化新概念.
- 这项研究为理解和设计基于硫化物材料的催化剂开辟了新的途径.
相关概念视频
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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.
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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...
Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
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.
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Reduction of Alkenes: Catalytic Hydrogenation
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 surface of...
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 surface of...
Heterogeneous Catalysis
Heterogeneous catalysis involves a catalyst in a different phase from the reactants. It is a process where the catalyst and the reactants are in distinct phases, typically solid and gas or liquid.Most heterogeneous catalysts are metals, metal oxides, or acids. The list includes transition metals like iron (Fe), cobalt (Co), nickel (Ni), palladium (Pd), platinum (Pt), chromium (Cr), manganese (Mn), tungsten (W), silver (Ag), and copper (Cu). These metals possess partially vacant d orbitals that...
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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.

