フォルメートの電気触媒性酸化により, [Ni((P(R) 2N(R') 2) 2 (((CH3CN) ]2+複合体によって形成される
Brandon R Galan1, Julia Schöffel, John C Linehan
1Chemical and Materials Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States.
Journal of the American Chemical Society
|June 23, 2011
まとめ
ニッケル複合体は,高効率で CO2 に形成酸化を触媒化し,基礎金属電触媒の画期的な進歩を表しています. これらの均質な触媒は,この重要な反応について報告されている最も高い速度を提供します.
科学分野:
- 協調化化学について
- エレクトロカタリシス.
- ホモゲーネスな触媒
背景:
- フォーマット酸化は,エネルギー変換と二酸化炭素利用における重要な反応です.
- 効率的で選択的な触媒の開発,特に土壌に豊富な金属からの開発は極めて重要です.
研究 の 目的:
- 電子触媒形式酸化のための新しいニッケル複合体を合成し,特徴づけること.
- これらの複合体の触媒的活動,運動,およびメカニズムを調査する.
主な方法:
- ニッケル複合体の合成と単結晶X線結晶学.
- サイクルボルトメトリーおよびターンオーバー周波数測定を含む電気化学的特徴付け.
- 反応メカニズムを明らかにするために,光譜分析を行います.
主要な成果:
- 新しく合成されたニッケル複合体は,フォーマット酸化のための高い電気触媒活性を示します.
- 触媒速度はホルマート濃度に依存し,濃度が高くても平原に達する.
- 観測された周回頻度は,均質なフォーマット酸化触媒で報告された最高です.
- リンガンドのペンダントアミンは,触媒活性に不可欠である.
結論:
- ニッケル複合体は,ホルマート酸化のための効果的な均質な電気触媒である.
- 提案されたメカニズムは,形式結合に続いて陽子と電子の移転を含む.
- これらの発見は,基礎金属を用いた持続可能な触媒プロセスの開発を進めています.
関連する概念動画
Formation of Complex Ions
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
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.
Reactivity of Enolate Ions
Enolate ions are formed by the acid–base reaction of a carbonyl compound with a base. This leads to deprotonation of the α hydrogen atom, leading to a resonance-stabilized enolate ion where one of the contributing structures is an oxyanion, which imparts additional stability. Therefore, the proton on the α carbon is more acidic in nature than that of other sp3-hybridized C–H bonds but less acidic than those in O–H bonds where the negative charge in the conjugate base is localized on the oxygen...
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
Nitrous acid is a relatively weak and unstable acid prepared in situ by the reaction of sodium nitrite and cold, dilute hydrochloric acid. In an acidic solution, the nitrous acid undergoes protonation when it loses water to form a nitrosonium ion—an electrophile. Nitrous acid reacts with primary amines to give diazonium salts. The reaction is called diazotization of primary amines.
Aldehydes and Ketones with HCN: Cyanohydrin Formation Mechanism
Cyanohydrins are formed when cyanide nucleophiles and carbonyl compounds like aldehydes and ketones react. A strong base, the cyanide ion, catalyzes cyanohydrin formation. The ions are generated from HCN under aqueous conditions. Once the cyanide ions are generated, the first step involves the nucleophilic attack of the cyanide ions on the electrophilic carbonyl carbon. This attack shifts the π electrons from the C=O to the oxygen atom forming the alkoxide ion intermediate. The alkoxide anion...
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Overview
Nitrous acid and nitric acids are two types of acids containing nitrogen, among which nitrous acid is weaker than nitric acid. Nitrous acid with a pKa value of 3.37 ionizes in water to give a nitrite ion and the hydronium ion.
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by water loss...
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by water loss...
![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)

