单原子与氧气空隙的合促进了酸性介质中的氧气演化反应
1State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China.
Journal of the American Chemical Society
|September 21, 2020
概括
研究人员在氧化物纳米片上使用单原子开发了一种新的氧化反应催化剂 (OER). 这种催化剂在酸性条件下表现出更好的活性和稳定性,提供了具有成本效益的解决方案.
科学领域:
- 材料科学
- 电化学
- 催化剂
背景情况:
- 在酸性介质中开发高效稳定的氧化演化反应电催化剂对于能源应用至关重要.
- 同时提高OER电催化剂的活性,提高稳定性和降低成本仍然是一个重大挑战.
研究的目的:
- 在超薄的NiCo2O4多孔纳米片 (Ir-NiCo2O4 NSs) 上制备单原子 (Ir-SAs) 的新策略.
- 在酸性介质中研究合成的Ir-NiCo2O4NS的OER性能和稳定性.
- 通过密度函数理论 (DFT) 的计算来阐明增强OER性能背后的机制.
主要方法:
- 用同电沉积方法在超薄的NiCo2O4多孔纳米板上合成单原子 (Ir-SAs).
- 在酸性介质中评估了电催化活性和稳定性,测量了超电位和电流密度.
- 在不同的超能值下计算了转换频率 (TOF).
- 进行密度函数理论 (DFT) 计算以了解电子结构和反应机制.
主要成果:
- 合成的Ir-NiCo2O4NS表现出优异的OER性能,在10mA cm-2下超低的240mV.
- 催化剂表现出长期稳定性,在酸性环境中运行70小时.
- 在300mV和370mV的超电位下,分别达到1.13和6.70s-1的高TOF.
- DFT的计算显示,表面电子交换和传输活动,由Ir-SA与氧气空缺 (VO) 的合促进,是提高性能的原因.
结论:
- 在酸中,Ir-NiCo2O4 NS是高活性和稳定的OER电催化剂.
- 在NiCo2O4纳米板上单个原子和氧空隙之间的协同效应是优化OER性能的关键.
- 该策略通过增强电子特性,促进水激活和氧稳定,为设计高效的电催化剂提供了通用方法.
相关概念视频
Oxidative Cleavage of Alkenes: Ozonolysis
12.4K
In ozonolysis, ozone is used to cleave a carbon–carbon double bond to form aldehydes and ketones, or carboxylic acids, depending on the work-up.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.
12.4K
Oxygenic Photosynthesis
560
Oxygenic photosynthesis is a fundamental process in which light energy is harnessed to drive the oxidation of water, leading to the production of molecular oxygen (O₂), adenosine triphosphate (ATP), and nicotinamide adenine dinucleotide phosphate (NADPH). This process is essential for sustaining aerobic life on Earth and is primarily carried out by cyanobacteria, algae, and plants. The core of oxygenic photosynthesis lies in the thylakoid membranes, where chlorophyll pigments facilitate...
560
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
12.2K
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.
12.2K
Oxidation-Reduction Reactions
74.2K
Oxidation–Reduction Reactions
74.2K
Redox Reactions
57.9K
Oxidation-reduction or redox reactions involve the transfer of electrons from one molecule or atom to another. When an atom gains an electron, another atom must lose an electron, meaning oxidation and reduction must occur together. Since the redox occurs in pairs, the atom that gets oxidized is also called the reducing agent or reductant, and the atom that is reduced is also called the oxidizing agent or oxidant. A straightforward way to remember the definitions of oxidation and reduction is...
57.9K
Redox Reactions
644
Redox reactions are vital biochemical processes that underpin energy metabolism in cells. These reactions involve the transfer of electrons between molecules, occurring in tandem as oxidation and reduction. Oxidation refers to the loss of electrons, while reduction denotes their gain. This coupling ensures the seamless flow of electrons through metabolic pathways. For example, in bacterial metabolism, glucose undergoes oxidation to carbon dioxide, while oxygen is simultaneously reduced to...
644


