セリウムベースの金属有機層は,二重光刺激によって水素進化反応を触媒化する
Yang Song1, Yunhong Pi1,2, Xuanyu Feng1
1Department of Chemistry, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, United States.
Journal of the American Chemical Society
|April 2, 2020
まとめ
最初のセリウムベースの金属有機層 (MOL) Ce6-BTBを合成し 光触媒による水素の進化のために機能化しました イリジウムまたはルテニウム複合体で改造されたMOLは,可視光の下で効率的な水素生成を達成しました.
科学分野:
- 材料科学
- キャタリシス
- 写真化学
背景:
- セリアのようなセリウムベースの物質は 触媒に不可欠です
- メタル・オーガニック層 (MOL) は,高度なアプリケーションのための調整可能な構造を提供します.
研究 の 目的:
- 最初のセリウムベースの金属有機層 (Ce6-BTB) を合成し,特徴づけます.
- 光触媒水素進化反応 (HER) の Ce6-BTB を機能化する.
- 機能化されたMOLにおける光触媒のメカニズムを調査する.
主な方法:
- Ce6-BTBの合成は,Ce6二次ビルディングユニット (SBU) とBTBリンクヤーを使用しています.
- イリジウムまたはルテニウム光敏感剤によるCe6-BTBの合成後の改変.
- 可視光下での光触媒水素進化反応 (HER) の測定
- 反応メカニズムを解明するための光物理学的および電気化学的研究.
主要な成果:
- Ce6-BTBは成功して合成され,Ce6-BTB-IrとCe6-BTB-Ruを生成しました.
- 機能化されたMOLは,高回転数 (1357 for Ir, 484 for Ru) を有する効率的な光触媒 HERを示した.
- Ce6 SBUと光敏感剤を含む新しい二重光刺激経路が特定されました.
結論:
- Ce6- BTB- IrとCe6- BTB- Ruは,可視光下でのHERの効果的な光触媒である.
- 光感受剤とCe6 SBUの接近は,効率的な電子転送に不可欠です.
- 二重光刺激メカニズムは光触媒活性を増強する.
関連する概念動画
02:50Catalysis
29.9K
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.
29.9K
01:26Photochemical Electrocyclic Reactions: Stereochemistry
2.1K
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
2.1K
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.8K
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...
3.8K
02:13Reduction of Alkenes: Catalytic Hydrogenation
13.8K
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...
13.8K
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
2.9K
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
2.9K
01:17Thermal Electrocyclic Reactions: Stereochemistry
2.4K
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
2.4K