同位素效应和水性臭氧和过氧分解的机制
Timothy M Lesko1, A J Colussi, Michael R Hoffmann
1W. M. Keck Laboratories, California Institute of Technology, Pasadena, California 91125, USA.
Journal of the American Chemical Society
|April 1, 2004
概括
过氧化是一种过氧化.
科学领域:
- 环境化学环境化学
- 氧化化学 有氧化化学
背景情况:
- 水性臭氧 (O3) 的反应性是由过氧化 (H2O2) 增强的,但底层机制尚不清楚.
- 一种涉及基 (.OH) 和超氧化物 (.O2-) 基的基链机制经常被提议用于在H2O2的存在下对臭氧分解.
研究的目的:
- 为了研究水性臭氧和过氧化的反应机制.
- 阐明激素与非激素途径在过子系统中的作用.
主要方法:
- 使用H2O/D2O溶剂同位素效应的动态研究.
- 实验性臭氧分解速率与来自激素链机制的预测进行比较.
主要成果:
- 根基机制准确地预测了臭氧在H2O中的分解,但在过氧 (O3 + H2O2) 中高估了它.
- 溶剂化实验表明,从臭氧+氧化离子 (HO2-) 反应中没有形成基质产物.
- 过子系统中的一个大的动态同位素效应 (KIE) 表明臭氧和HO2-之间的非激素,化物转移反应,形成HO3-和O2.
结论:
- 在氧系统中,通过H2O2增强臭氧反应能力主要是由非激素转移机制驱动的,而不是激素连锁反应.
- 形成的HO3-物种可能与最近发现的杀菌三氧化物有关.
更多相关视频
11:38In situ FTIR Spectroscopy as a Tool for Investigation of Gas/Solid Interaction: Water-Enhanced CO2 Adsorption in UiO-66 Metal-Organic Framework
Published on: February 1, 2020
08:30A Complete Method for Evaluating the Performance of Photocatalysts for the Degradation of Antibiotics in Environmental Remediation
Published on: October 6, 2022
相关概念视频
Water: A Bronsted-Lowry Acid and Base
The reaction between a Brønsted-Lowry acid and water is called acid ionization. For example, when hydrogen fluoride dissolves in water and ionizes, protons are transferred from hydrogen fluoride molecules to water molecules, yielding hydronium ions and fluoride ions:
Common Ion Effect
Compared with pure water, the solubility of an ionic compound is less in aqueous solutions containing a common ion (one also produced by dissolution of the ionic compound). This is an example of a phenomenon known as the common ion effect, which is a consequence of the law of mass action that may be explained using Le Châtelier’s principle. Consider the dissolution of silver iodide:
Factors Affecting Solubility
Compared with pure water, the solubility of an ionic compound is less in aqueous solutions containing a common ion (one also produced by dissolution of the ionic compound). This is an example of a phenomenon known as the common ion effect, which is a consequence of the law of mass action that may be explained using Le Chȃtelier’s principle. Consider the dissolution of silver iodide:
Balancing Redox Equations
Electrochemistry is the science involved in the interconversion of electrical and chemical reactions. Such reactions are called reduction-oxidation, or redox reactions. These important reactions are defined by changes in oxidation states for one or more reactant elements and include a subset of reactions involving the transfer of electrons between reactant species. Electrochemistry as a field has evolved to yield sufficient insights on the fundamental principles of redox chemistry and multiple...
Radical Autoxidation
The oxidation of an organic compound in the presence of air or oxygen is called autoxidation. For example, cumene reacts with oxygen to form hydroperoxide. Autoxidation involves initiation, propagation, and termination steps. Many organic compounds are susceptible to autoxidation—especially ethers in the presence of oxygen, which form hydroperoxides. Even though this reaction is slow, old ether bottles contain small amounts of peroxide, which leads to laboratory explosions during ether...
Microbial Bioremediation of Pesticides
Pesticides often feature structurally complex chemical architectures, incorporating halogen groups and multiple aromatic rings. These characteristics confer high chemical stability, rendering many pesticides resistant to natural degradation processes. This resistance poses significant environmental concerns, as persistent pesticide residues can accumulate in ecosystems and affect non-target organisms.Despite the inherent stability of many pesticides, certain microorganisms possess the metabolic...
