气相氢氟烃和氢氟烯烃与·OH反应的量子化学计算方法筛选  

Screening of quantum chemical method for the reactions of hydrofluorocarbons and hydrofluoroolefins with·OH in the Atmosphere

作　　者：丁保君[1] 姜琦 夏德铭 马芳芳 陈景文[2] DING Baojun;JIANG Qi;XIA Deming;MA Fangfang;CHEN Jingwen(School of Chemical Engineering,Dalian University of Technology,Dalian,116024,China;Key Laboratory of Industrial Ecology and Environmental Engineering(Ministry of Education),Department of Environmental Science and Technology,Dalian University of Technology,Dalian,116024,China)

机构地区：[1]大连理工大学化工学院,大连116024 [2]工业生态与环境工程教育部重点实验室,大连市化学品风险防控及污染防治技术重点实验室,大连理工大学环境学院,大连116024

出　　处：《环境化学》2023年第10期3256-3264,共9页Environmental Chemistry

基　　金：国家重点研究发展计划(2018YFC1801604,2018YFE0110700);国家自然科学基金(22136001)资助.

摘　　要：氢氟烃(HFCs)和氢氟烯烃(HFOs)常被用作氢氯氟烃的替代物.为评估HFCs和HFOs是否可以理想替代氢氯氟烃,需要对其大气转化进行充分研究,尤其需要充分了解其大气持久性的信息.目前用于评估化学品大气持久性的重要参数气相羟基自由基(·OH)二级反应速率常数(k_(OH))的数据量尚不能满足多种HFCs和HFOs的评估.因此有必要发展能够快速预测k_(OH)的方法.量子化学计算方法具有高效、准确的优点,是预测k_(OH)的重要手段.然而目前研究使用的量子化学方法纷繁复杂,亟需筛选适合HFCs和HFOs的量子化学方法.本研究基于3种HFCs(CF_(3)CF_(2)H、CF_(3)CH_(2)CF_(3)和CF_(3)CF_(2)(CHF_(2)CF_(3))和2个HFOs(CF_(2)CH_(2)和CF_(3)CH_(2)CF_(3))的实验数据,从多种热力学参数计算方法和动力学计算方法中筛选适用于计算HFCs和HFOs气相k_(OH)的方法.研究结果表明,通过对比lgk_(OH)的实测值与不同计算方法所得计算值之间的平均绝对误差(MAE),利用Skodje-Truhlar隧道效应校正系数(κS)修正传统过渡态理论(TST),再结合M06-2X-D3/def2-TZVP//M06-2X/cc-pVDZ水平的密度泛函理论(DFT)计算HFCs的k_(OH)效果最好,其MAE值为0.17;采用Wigner隧道效应校正系数(κ_(W))修正的TST结合M06-2X-D3/aug-ccpVTZ//M06-2X/cc-pVDZ(MAE=0.50)的方法计算HFOs的k_(OH)效果最好;而κ_(S)修正TST的M06-2XD3/aug-cc-pVTZ//M06-2X/cc-pVDZ(MAE=0.34)或M06-2X-D3/jul-cc-pVTZ//M06-2X/cc-pVDZ(MAE=0.35)方法都适用于计算HFCs和HFOs的k_(OH).本研究筛选的方法为快速、准确计算HFCs和HFOs的k_(OH)及评估其大气持久性提供了方法支撑.Hydrofluorocarbons(HFCs)and hydrofluoroolefins(HFOs)are mainly employed to substitute hydrochlorofluorocarbons.In order to evaluate whether the HFCs and HFOs are ideal alternatives for hydrochlorofluorocarbons or not,it is necessary to fully explore their atmospheric transformation,especially the information atmospheric persistence.To date,the quantity of secondorder reaction rate constants(k_(OH))for chemicals reacting with hydroxyl radicals(·OH),which are essential parameters to characterize the atmospheric persistence of HFCs and HFOs,cannot meet the needs of atmospheric persistence assessment for HFCs and HFOs.Therefore,it is necessary to develop a method that can predict the k_(OH) values efficiently.Considering the efficiency and accuracy of quantum chemical calculation,quantum chemical calculation is an important way to predict the k_(OH) values.However,the quantum chemistry methods used in the current research are complex,and it is urgent to screen the quantum chemistry methods that are suitable for HFCs and HFOs.In this study,suitable methods for predicting the atmospheric k_(OH) values of HFCs and HFOs were selected from a variety of thermodynamic parameter calculation methods and kinetics calculation methods based on the experimental data of 3 HFCs(CF_(3)CF_(2)H,CF_(3)CH_(2)CF_(3),and CF_(3)CF_(2)(CHF)_(2)CF_(3))and 2 HFOs(CF_(2)CH_(2) and CF_(3)CH_(2)CF_(3)).The research results show that by comparing the mean absolute error(MAE)between the experimental lgk_(OH) values and the lgk_(OH) values calculated by different theoretical methods,the method employing the traditional transition state theory(TST)modified with the Skodje-Truhlar tunnel effect correction coefficient(κ_(S))and combining with the density functional theory(DFT)at the M06-2X-D3/def2-TZVP//M06-2X/cc-pVDZ level has the best effect on calculating the k_(OH) of HFCs accurately,whose MAE was 0.17;The method employing TST method modified with Wigner transmission coefficient(κ_(W))and combining with the M06-2X-D3/aug-ccpVTZ//M06-2X/cc-pVDZ(

关 键 词：氢氟烃 (HFCs) 氢氟烯烃 (HFOs) ·OH 量子化学计算 密度泛函理论(DFT) 动力学 

分 类 号：X51[环境科学与工程—环境工程]