电极-电解质接口的分子尺度结构:在水性硫酸中的情况
Cheng Hao Wu1,2, Tod A Pascal3, Artem Baskin3
1Department of Chemistry , University of California , Berkeley , California 94720 , United States.
Journal of the American Chemical Society
|October 30, 2018
概括
研究人员揭示了硫酸中的电极电气双层 (EDL) 的结构. EDL由吸附的硫酸盐离子和水合的离子组成,促进了对电化学接口的理解.
科学领域:
- 电化学
- 表面科学
- 光谱学
背景情况:
- 了解电化的固体-液体接口对于异质反应至关重要.
- 接口上的分子组成和电子结构决定了反应途径.
研究的目的:
- 在水性硫酸中确定电极界面区域的化学成分.
- 在电化学条件下阐明电双层 (EDL) 的结构.
主要方法:
- 在电子产量模式 (EY-XAS) 中对接口敏感的X射线吸收光谱.
- 第一个原则是电子结构计算.
- 多个尺度的模拟.
主要成果:
- EDL包括吸附的硫酸盐离子和水合离子在0.7和1.3V之间与Ag/AgCl.
- 没有发现二硫酸盐或Pt-O/Pt-OH物种的证据.
- 建立了EY-XAS作为一种强大的埋藏界面分析工具.
结论:
- 解决了长期存在的EDL结构问题.
- 证明了EY-XAS在电化学中研究固体液体接口的实用性.
- 提供有关电化学设备的界面过程的见解.
相关概念视频
Acid Strength and Molecular Structure
33.1K
Binary Acids and Bases
In the absence of any leveling effect, the acid strength of binary compounds of hydrogen with nonmetals (A) increases as the H-A bond strength decreases down a group in the periodic table. For group 17, the order of increasing acidity is HF < HCl < HBr < HI. Likewise, for group 16, the order of increasing acid strength is H2O < H2S < H2Se < H2Te. Across a row in the periodic table, the acid strength of binary hydrogen compounds increases with increasing...
In the absence of any leveling effect, the acid strength of binary compounds of hydrogen with nonmetals (A) increases as the H-A bond strength decreases down a group in the periodic table. For group 17, the order of increasing acidity is HF < HCl < HBr < HI. Likewise, for group 16, the order of increasing acid strength is H2O < H2S < H2Se < H2Te. Across a row in the periodic table, the acid strength of binary hydrogen compounds increases with increasing...
33.1K
Molecular Structure and Acidity
20.9K
An acid can be deprotonated to form a conjugate base or an anion. If the produced anion is more stable, then the acid is stronger. On the contrary, if the anion is unstable, then the acid is weaker. Hence, to determine the acidity of the compound, the stability of its conjugate base is studied using various factors.
The size effect explains the change in atomic size on acidity. When comparing the acids formed from elements that belong to the same column in the periodic table, their atomic sizes...
The size effect explains the change in atomic size on acidity. When comparing the acids formed from elements that belong to the same column in the periodic table, their atomic sizes...
20.9K
Electrolyte and Nonelectrolyte Solutions
71.9K
Substances that undergo either a physical or a chemical change in solution to yield ions that can conduct electricity are called electrolytes. If a substance yields ions in solution, that is, if the compound undergoes 100% dissociation, then the substance is a strong electrolyte. Complete dissociation is indicated by a single forward arrow. For example, water-soluble ionic compounds like sodium chloride dissociate into sodium cations and chloride anions in aqueous solution.
71.9K
The Sulfur Cycle
51.9K
Sulfur, an important element in the chemical makeup of proteins, is recycled through the atmosphere and aquatic and terrestrial environments. Found in the atmosphere as sulfur dioxide (SO2), sulfur is released by decaying organisms, weathered rocks, geothermal vents, volcanos, and burning fossil fuels. It is deposited into the ecosystem, cycled through the biotic community, and either released back into the atmosphere as gas or deposited in marine sediment for long-term storage and eventual...
51.9K
Chemical Reactions in Aqueous Solutions
72.4K
Chemical substances interact in many different ways. Certain chemical reactions exhibit common patterns of reactivity. Due to the vast number of chemical reactions, it becomes necessary to classify them based on the observed patterns of interaction.
72.4K
pH Scale
79.8K
Hydronium and hydroxide ions are present both in pure water and in all aqueous solutions, and their concentrations are inversely proportional as determined by the ion product of water (Kw). The concentrations of these ions in a solution are often critical determinants of the solution’s properties and the chemical behaviors of its other solutes. Two different solutions can differ in their hydronium or hydroxide ion concentrations by a million, billion, or even trillion times. A common means of...
79.8K


