![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)
潜在に依存した電気触媒経路:ニッケルベースの水素進化触媒の機械的調査のためのpKaによる反応性の制御
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
まとめ
この研究は,ニッケルベースの水素進化触媒のメカニズムを詳細に説明し,陽子減少を誘導する2つの異なる経路 (ECECとEECC) を明らかにしています. 動力学的分析により,水素生成の重要な段階が明らかになった.
科学分野:
- 無機化学
- 電気化学
- カタリシス
背景:
- ニッケル複合体は水素進化の有望な触媒です
- これらの触媒のメカニズムを理解することは 効率を最適化するために不可欠です
研究 の 目的:
- 水素進化触媒 [Ni(P2(Ph) N2 ((Ph)) 2 ((CH2CN) ]の詳細なメカニズム分析を行う.
- 陽子還元触媒に含まれる異なるメカニズム (ECEC と EECC) を明らかにする.
- 水素進化の基本的なステップの運動を決定する.
主な方法:
- サイクル電圧測定を含む電気化学分析
- 時間解像度スペクトロスコーピー (停止フロー)
- ピークシフトと波の足の分析を用いた運動測定.
主要な成果:
- 触媒は2つのリドックスカップル (Ni(II/I) を−0.83VとNi(I/0) を−1.03V対Fc(+/0) で表している.
- 2つの異なる触媒経路,ECECとEECCが陽子還元のために特定されました.
- ニッケル (II) 水素の中間形成の速度定数 (k1 = 1.2-6.5 × 10^6 M^-1 s^-1) を決定した.
- ハイドリド中介物質と潜在的なオフサイクル中介物質の反応性をモニタリングした.
結論:
- 触媒は,適用されたポテンシャルに応じて,ECECとEECCという2つの異なるメカニズムで動作します.
- 動力学的データは水素進化の基本的なステップの洞察を提供します.
- 発見は,触媒プロセスにオフサイクルの中間物質の関与を示唆しています.
関連する概念動画
02:50Catalysis
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
01:22Heterogeneous 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
02:13Reduction 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
02:17Reduction 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
01:30Processes 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
02:24Reduction 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