通过旋转极化和电子状态在灵活的范德瓦尔斯膜催化剂中的可调性来增强氧气演化反应
Hang Xu1,2, Ji Qi1,2, Yuan Zhang2
1Functional Materials and Acousto-Optic Instruments Institute, School of Instrumentation Science and Engineering, Harbin 150080, China. weiminglv@hit.edu.cn.
Physical chemistry chemical physics : PCCP
|July 25, 2023
概括
将应变和磁场应用于La0.7Sr0.3MnO3 (LSMO) 催化剂,通过操纵自旋状态和电子特性,显著提高了氧化演化反应 (OER) 的性能.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 催化剂是一种催化剂.
背景情况:
- 矿过渡金属氧化物 (TMO) 为催化剂设计提供原子级控制.
- 了解旋转在氧化演化反应 (OER) 等电化学过程中的作用至关重要,但由于轨道相关性而复杂.
- La0.7Sr0.3MnO3 (LSMO) 是一种铁磁材料,其催化潜力受到研究.
研究的目的:
- 研究应变工程和磁场对LSMO催化剂的OER性能的影响.
- 阐明底层机制,特别是旋转的作用,在应变调制和磁性影响的OER中.
- 为了证明设计柔性磁性电催化剂的潜力.
主要方法:
- 直接沉积LSMO薄膜在柔性基板上.
- 在LSMO薄膜上施加拉伸应变.
- 催化剂暴露在外部磁场中.
- 氧化演化反应 (OER) 的电化学测量.
主要成果:
- 在LSMO上的拉伸应变 (+0.2%) 由于薄弱的Mn-O化学吸收,使OER性能提高了30%.
- 5kOe磁场和+0.2%应变的组合将OER性能提高了约87%,并将超电位降低了22%.
- 在4%的应变和5kOe磁场下观察到显著的OER性能变化 (∼153%),这与O2的三重状态和减少的旋转潜力有关.
结论:
- 应变工程和磁场是提高像LSMO这样的铁磁材料中OER催化力的有效策略.
- 观察到的磁响应主要归因于O2的三重状态,影响旋转极化和减少旋转潜力.
- 这项工作为通过控制旋转和电子状态来开发先进,灵活的磁性电催化剂提供了基础.
相关概念视频
01:26Photochemical Electrocyclic Reactions: Stereochemistry
1.9K
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
1.9K
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
2.4K
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.
2.4K
02:50Catalysis
27.1K
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.
27.1K
02:21Oxidation of Alkenes: Syn Dihydroxylation with Potassium Permanganate
11.9K
Alkenes can be dihydroxylated using potassium permanganate. The method encompasses the reaction of an alkene with a cold, dilute solution of potassium permanganate under basic conditions to form a cis-diol along with a brown precipitate of manganese dioxide.
11.9K
01:13Introduction to Mechanisms of Enzyme Catalysis
8.3K
For many years, scientists thought that enzyme-substrate binding took place in a simple "lock-and-key" fashion. This model stated that the enzyme and substrate fit together perfectly in one instantaneous step. However, current research supports a more refined view scientists call induced fit. The induced-fit model expands upon the lock-and-key model by describing a more dynamic interaction between enzyme and substrate. As the enzyme and substrate come together, their interaction causes...
8.3K
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
10.4K
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
10.4K