Quantum Chemical Study on 路Cl-Initiated Atmospheric Degradation of Monoethanolamine

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• 作者：Hong-Bin Xie ; Fangfang Ma ; Yuanfang Wang ; Ning He ; Qi Yu ; Jingwen Chen
• 刊名：Environmental Science & Technology
• 出版年：2015
• 出版时间：November 17, 2015
• 年：2015
• 卷：49
• 期：22
• 页码：13246-13255
• 全文大小：604K
• ISSN：1520-5851

文摘

Recent findings on the formation of 路Cl in continental urban areas necessitate the consideration of 路Cl initiated degradation when assessing the fate of volatile organic pollutants. Monoethanolamine (MEA) is considered as a potential atmospheric pollutant since it is a benchmark and widely utilized solvent in a leading CO₂ capture technology. Especially, 路Cl may have specific interactions with the N atom of MEA, which could make the MEA + 路Cl reaction have different pathways and products from those of the MEA + 路OH reaction. Hence, 路Cl initiated reactions with MEA were investigated by a quantum chemical method [CCSD(T)/aug-cc-pVTZ//MP2/6-31+G(3df,2p)] and kinetics modeling. Results show that the overall rate constant for 路Cl initiated H-abstraction of MEA is 5 times faster than that initiated by 路OH, and the tropospheric lifetimes of MEA will be overestimated by 6鈥?6% when assuming that [路Cl]/[路OH] = 1鈥?0% if the role of 路Cl is ignored. The MEA + 路Cl reaction exclusively produces MEA-N that finally transforms into several products including mutagenic nitramine and carcinogenic nitrosamine via further reactions with O₂/NO_x, and the contribution of 路Cl to their formation is about 25鈥?50% of that of 路OH. Thus, it is necessary to consider 路Cl initiated tropospheric degradation of MEA for its risk assessment.