揭示了电解质依赖于COOOH催化氧进化反应的动力学
Hongnan Jia1, Na Yao2, Can Yu3
1College of Chemistry and Molecular Sciences, Wuhan University Hubei, 430072, Wuhan, P. R. China.
Angewandte Chemie (International ed. in English)
|October 21, 2023
概括
电解质间隔到氧化 (CoOOH) 催化剂中,增强氧演化反应 (OER) 活性. 较大的子增加了层间距,通过电子结构修改提高了催化性能.
科学领域:
- 电触媒溶解是一种电触媒.
- 材料科学 材料科学 材料科学
- 表面化学 表面化学
背景情况:
- 电解质阴离子对电催化动力学的影响得到了广泛的观察,但在机制上仍有争议.
- 了解阴离子影响对于优化氧演化反应 (OER) 等电催化过程至关重要.
研究的目的:
- 阐明电解质在OER期间影响氧化 (CoOOH) 催化剂性能的机制.
- 为了研究离子体大小,催化剂结构和OER活性之间的相关性.
主要方法:
- 使用X射线衍射 (XRD) 和高分辨率传输电子显微镜 (HRTEM) 来观察结构变化.
- 射线吸收光谱 (XAS),现场拉曼光谱,现场紫外线/Vis光谱,循环电压测量 (CV),以及用于探测电子结构和反应中间体的理论计算.
主要成果:
- 电解质 (Cs +,K +,Na +,Li +) 插入CoOOH层,较大的会导致更大的间层扩张和增强OER活动.
- 阴离子间隔修改了的氧化状态和Co-O键的长度,优化了d波段中心和氧介质吸附.
- 这一过程促进了活跃的Co ((IV) 物种的形成,并降低了OER中速率决定步骤的能量障碍.
结论:
- 这项研究提供了CoOOH催化剂中依赖电解质离子的OER动力学的详细机制.
- 较大的阴离子的间隙增强了OER活动,通过结构和电子修改催化剂.
- 研究结果提供了超越OER的阴离子向电催化机制的见解.
相关概念视频
03:00Electrolysis
26.6K
In a galvanic cell, the electrical work is done by a redox system on its surroundings as electrons produced by the spontaneous redox reactions are transferred through an external circuit. Alternatively, an external circuit does work on a redox system by imposing a voltage sufficient to drive an otherwise nonspontaneous reaction in a process known as electrolysis. For instance, recharging a battery involves the use of an external power source to drive the spontaneous (discharge) cell reaction in...
26.6K
01:23Reactivity of Enolate Ions
2.5K
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...
2.5K
02:45E2 Reaction: Kinetics and Mechanism
10.3K
SN2 substitutions and E2 eliminations of alkyl halides proceed via a concerted pathway. While the nucleophile attacks the alpha carbon in SN2 reactions, it functions as a strong base and abstracts a beta hydrogen in the E2 mechanism. The rate-limiting transition state in E2 elimination reactions is characterized by partially broken carbon–hydrogen and carbon–halogen bonds and a partially formed pi bond between the alpha and beta carbons. The beta hydrogen and halide are eliminated...
10.3K
02:50Catalysis
27.0K
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.
27.0K
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
2.3K
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.
2.3K
03:11Oxidation-Reduction Reactions
65.1K
Oxidation–Reduction Reactions
65.1K