Competing esterification and oligomerization reactions of typical long-chain alcohols to secondary organic aerosol formation  

作　　者：Jiaxin Wang Xiaohui Ma Yuemeng Ji Yongpeng Ji Yanpeng Gao Yuqi Xiao Guiying Li Taicheng An 

机构地区：[1]Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control,Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health,Institute of Environmental Health and Pollution control,Guangdong University of Technology,Guangzhou 510006,China [2]Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control,Key Laboratory of City Cluster Environmental Safety and Green Development,School of Environmental Science and Engineering,Guangdong University of Technology,Guangzhou 510006,China

出　　处：《Journal of Environmental Sciences》2023年第4期103-112,共10页环境科学学报（英文版）

基　　金：financially supported by the Natural Science Foundation of Guangdong Province,China (No.2019B151502064);the National Natural Science Foundation of China (Nos.42077189 and 4201001008);the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (No.2017BT01Z032);the Innovation Team Project of Guangdong Provincial Department of Education(No.2017KCXTD012);the Science and Technology Key Project of Guangdong Province,China (No.2019B110206002)。

摘　　要：Organosulfate (OSA) nanoparticles,as secondary organic aerosol (SOA) compositions,are ubiquitous in urban and rural environments.Hence,we systemically investigated the mechanisms and kinetics of aqueous-phase reactions of 1-butanol/1-decanol (BOL/DOL) and their roles in the formation of OSA nanoparticles by using quantum chemical and kinetic calculations.The mechanism results show that the aqueous-phase reactions of BOL/DOL start from initial protonation at alcoholic OH^(-)groups to form carbenium ions (CBs),which engage in the subsequent esterification or oligomerization reactions to form OSAs/organosulfites (OSIs) or dimers.The kinetic results reveal that dehydration to form CBs for BOL and DOL reaction systems is the rate-limiting step.Subsequently,about 18%of CBs occur via oligomerization to dimers,which are difficult to further oligomerize because all reactive sites are occupied.The rate constant of BOL reaction system is one order of magnitude larger than that of DOL reaction system,implying that relative short-chain alcohols are more prone to contribute OSAs/OSIs than long-chain alcohols.Our results reveal that typical long-chain alcohols contribute SOA formation via esterification rather than oligomerization because OSA/OSI produced by esterification engages in nanoparticle growth through enhancing hygroscopicity.

关 键 词：Long-chain alcohols Organosulfates Aqueous phase reaction Reaction mechanisms Secondary organic aerosol 

分 类 号：X513[环境科学与工程—环境工程]