Hydrolysis of ketene catalysed by nitric acid and water in the atmosphere
Hydrolysis of ketene catalysed by nitric acid and water in the atmosphere
复制标题
硝酸和大气中的水催化乙烯酮水解
DOI：
10.1071/en19202
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发表时间：
2020-02
期刊：
影响因子：
--
通讯作者：
Bo Long
中科院分区：
文献类型：
--
作者：
Xu Fang;Xing-Feng Tan;Ze-Gang Dong;Da-Sen Ren;Bo Long
环境背景气相乙烯酮水解形成乙酸的详细机制对于了解某些大气污染物的形成至关重要。本研究探讨了硝酸和水对大气中乙烯酮水解的影响。计算结果表明，在大气限水环境下，硝酸是乙烯酮水解生成乙酸的有效催化剂。摘要 采用量子化学方法和传统的 Eckart 隧道效应过渡态理论研究了硝酸和水催化的乙烯酮气相水解和 1,1-烯二醇的单分子反应。理论计算结果表明，硝酸对乙烯酮气相水解具有较强的催化作用。直接反应机理路径的计算能垒从乙烯酮与水反应中的 42.10 kcal mol−1 降低到 HNO3 催化下乙烯酮与水反应中的 3.40 kcal mol−1。硝酸的催化能力在1,1-烯二醇的氢转移反应中得到进一步证明，因为1,1-烯二醇单分子反应的能垒从44.92 kcal mol−1降低到-4.51 kcal mol−1。此外，计算结果表明，在HNO3和(H2O)n (n = 1, 2)催化下乙烯酮与水的反应中，随着额外水分子的增加，直接和间接机理路径之间存在竞争。动力学计算结果表明，CH2=C=O + H2O + HNO3反应在大气气相中非常显着，而其他反应由于反应速率慢而可以忽略不计。但与CH2=C=O + OH反应相比，CH2=C=O + H2O + HNO3反应非常缓慢，无法与CH2=C=O + OH反应竞争。 CH2=C=O + OH是乙烯酮在大气气相中的主要消除途径。我们的研究结果表明，乙酸可能是通过乙烯酮在水、气溶胶和云滴表面的大气限水环境中水解而形成的。
Environmental context The detailed mechanism of hydrolysis of gas-phase ketene to form acetic acid is critical for understanding the formation of certain atmospheric contaminants. This study explores the effect of nitric acid and water on the hydrolysis of ketene in the atmosphere. The calculated results show that nitric acid is an effective catalyst in the hydrolysis of ketene to form acetic acid in atmospheric water-restricted environments. Abstract The gas-phase hydrolysis of ketene and the unimolecular reaction of 1,1-enediol catalysed by nitric acid and water have been investigated using quantum chemical methods and conventional transition state theory with Eckart tunnelling. The theoretical calculation results show that nitric acid exerts a strong catalytic effect on the hydrolysis of ketene in the gas-phase. The calculated energy barrier for the direct reaction mechanistic pathway is reduced from 42.10 kcal mol−1 in the reaction of ketene with water to 3.40 kcal mol−1 in the reaction of ketene with water catalysed by HNO3. The catalytic ability of nitric acid is further proven in the hydrogen shift reaction of 1,1-enediol because the energy barrier of the unimolecular reaction of 1,1-enediol is decreased from 44.92 kcal mol−1 to −4.51 kcal mol−1. In addition, the calculated results indicate that there is competition between the direct and indirect mechanistic pathways with the increase of additional water molecules in the reaction of ketene with water catalysed by HNO3 and (H2O)n (n = 1, 2). The calculated kinetics results show that the CH2=C=O + H2O + HNO3 reaction is significant in the gas phase of the atmosphere and the other reactions are negligible owing to the slow reaction rates. However, compared with the CH2=C=O + OH reaction, the CH2=C=O + H2O + HNO3 reaction is very slow and cannot compete with the CH2=C=O + OH reaction. CH2=C=O + OH is the main elimination pathway of ketene in the gas phase of the atmosphere. Our findings reveal that acetic acid may be formed through the hydrolysis of ketene in atmospheric water-restricted environments of the surfaces of aqueous, aerosol and cloud droplets.
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影响因子：
1.1
作者：
M. Nguyen;Greet Raspoet
通讯作者：
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影响因子：
--
作者：
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通讯作者：
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影响因子：
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作者：
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通讯作者：
SCHULTEFROHLINDE, D
影响因子：
5.5
作者：
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影响因子：
2.8
作者：
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通讯作者：
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