潜在依赖的电催化途径:控制pKa的反应性,用于对基化催化剂的机械研究
Eric S Rountree1, Jillian L Dempsey1
1Department of Chemistry, University of North Carolina , Chapel Hill, North Carolina 27599-3290, United States.
Journal of the American Chemical Society
|October 10, 2015
概括
这项研究详细介绍了基进化催化剂的机制,揭示了驱动质子减少的两个不同的途径 (ECEC和EECC). 动力分析揭示了生产的关键步骤.
科学领域:
- 无机化学
- 电化学
- 催化剂
背景情况:
- 复合物是进化的有希望的催化剂.
- 了解这些催化剂的机械路径对于优化它们的效率至关重要.
研究的目的:
- 进行演变催化剂[Ni ((P2 ((Ph)) N2 ((Ph)) 2 ((CH2CN)) ]的详细机械分析.
- 阐明参与质子还原催化的不同机制 (ECEC和EECC).
- 确定进化的基本步骤的动力学.
主要方法:
- 电化学分析包括循环电压测量.
- 时间分辨率光谱 (停止流).
- 使用峰值转移和波底分析进行动力测量.
主要成果:
- 催化剂表现出两种氧化还原对 (Ni(II/I) 在 -0.83 V 和 Ni(I/0) 在 -1.03 V 与 Fc(+/0)).
- 确定了两个不同的催化途径,即ECEC和EECC.
- 确定了 (II) 水化物中间形成的速率常数 (k1 = 1.2-6.5 × 10^6 M^-1 s^-1).
- 监测了化物中间体和潜在的循环外中间体的活性.
结论:
- 催化剂通过两种不同的机制运行,即ECEC和EECC,这取决于所应用的潜力.
- 动力学数据提供了有关进化的基本步骤的见解.
- 这些发现表明在催化过程中涉及一个循环之外的中间体.
相关概念视频
Catalysis
32.3K
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.
32.3K
Heterogeneous Catalysis
109
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...
109
Reduction of Alkenes: Catalytic Hydrogenation
14.9K
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...
14.9K
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
4.0K
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...
4.0K
Processes at Electrodes
74
The electrode interacts with ions in the electrolyte solution at its interface. The rate of oxidation and reduction depends on the speed at which electrons can transfer through this interface. As ions attach to or leave the electrode surface, the electrode acquires a charge, and an electrical potential forms across the interface, making the process more difficult to reach equilibrium. The charge on the electrode affects the local ion concentrations in the solution, though thermal motion...
74
Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
9.5K
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.
9.5K
![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)

