関連する実験動画

Updated: Sep 16, 2025

Hydrogen Production and Utilization in a Membrane Reactor

Hydrogen Production and Utilization in a Membrane Reactor

Published on: March 10, 2023

競合する経路を空間的に隔離することによって,電気化学的水素化経路の解明

Jiguang Zhang^1,2, Chengyi Zhang³, Sibo Wang¹

¹Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 117585, Republic of Singapore.

Journal of the American Chemical Society

|July 11, 2025

まとめ

電気化学的水素化は,イーリー-リデアルとラングミュア-ヒンシェルウッドの2つの経路で発生します. この研究は,ラングミュア・ヒンシェルウッドがより大きな運動同位体効果を持ち,製品の選択性に影響を与えることを示しています.

科学分野:

電気化学
化学反応メカニズム

背景:

電気化学的水素化は,エリ・リデアルまたはラングミュア・ヒンシェルウッドメカニズムを通じて行われます.
経路の競争を理解することは,反応の選択性と速度にとって極めて重要です.

研究の目的:

電気化学的水素化におけるエリ・リデアルとラングミュア・ヒンシェルウッド経路の運動同位体効果を区別する.
ステリック障害などの経路の好みに影響する要因を調査する.

主な方法:

ラングミュア・ヒンシェルウッド経路を隔離するためにパラジアム膜反応炉を使用した.
H2O/D2O電解質を用いた運動同位体効果 (KIE) の測定を行った.
実験結果を裏付けるために理論的シミュレーションを行った.

主要な成果:

Langmuir-Hinshelwood経路は,Eley-Rideal経路よりも大きな運動同位体効果を示しています.
Eley-Rideal経路は,混合H2O/D2O電解質によるデウテリウム結合がより高いことを示している.
ステリック障害はラングミュア-ヒンシェルウッド経路に好意的だ

結論:

水素化経路の明確な運動行動が解明された.
発見は,電気化学的水素化における計算モデリングと触媒設計のための洞察を提供します.

さらに関連する動画

Developing Photosensitizer-Cobaloxime Hybrids for Solar-Driven H2 Production in Aqueous Aerobic Conditions

Developing Photosensitizer-Cobaloxime Hybrids for Solar-Driven H2 Production in Aqueous Aerobic Conditions

Published on: October 5, 2019

Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase

Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase

Published on: December 4, 2017

関連する概念動画

Reduction of Alkenes: Asymmetric Catalytic Hydrogenation

Reduction of Alkenes: Asymmetric Catalytic Hydrogenation

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...

Reduction of Alkenes: Catalytic Hydrogenation

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...

Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule

Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule

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...

Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation

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.

Regioselectivity of Electrophilic Additions-Peroxide Effect

Regioselectivity of Electrophilic Additions-Peroxide Effect

In the presence of organic peroxides, the addition of hydrogen bromide to an alkene yields the isomer that is not predicted by Markovnikov’s rule. For example, the addition of hydrogen bromide to 2-methylpropene in the presence of peroxides gives 1-bromo-2-methylpropane. This addition reaction proceeds via a free radical mechanism, which reverses the regioselectivity. The free radical reaction mechanism involves three stages: initiation, propagation, and termination.

Catalysis

Catalysis

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.