液滴气-液界面上HOSO_(2)水解反应机制研究  

The hydrolysis reaction mechanism of HOSO_(2)at the air-water interface

作　　者：杨鸡换 郭晓凯 杨彦龙 李瑞妹 张田雷[1] YANG Jihuan;GUO Xiaokai;YANG Yanlong;LI Ruimei;ZHANG Tianlei(School of Chemical and Environmental Science,Shaanxi University of Technology,Hanzhong 723000,China;School of Mathematics and Computer Science,Shaanxi University of Technology,Hanzhong 723000,China)

机构地区：[1]陕西理工大学化学与环境科学学院,陕西汉中723000 [2]陕西理工大学数学与计算机科学学院,陕西汉中723000

出　　处：《陕西理工大学学报(自然科学版)》2025年第2期16-21,共6页Journal of Shaanxi University of Technology:Natural Science Edition

基　　金：国家自然科学基金项目(22073059)。

摘　　要：大气中的硫酸与酸雨、雾霾的形成以及气候变化等环境问题密切相关,传统知识认为大气中的硫酸主要是通过SO_(3)水解而形成的,然而该机制并不能解释大气中高的硫酸浓度来源。基于此,研究了液滴气-液界面上HOSO_(2)水解产生硫酸的新途径。经典分子动力学模拟结果表明,在150 ns的模拟时间内,HOSO_(2)停留在液滴气-液界面上的概率占62%。50条BOMD分子动力学模拟结果进一步发现,HOSO_(2)可以通过直接(HOSO_(2)+(H_(2)O)_(191)→H_(2)SO_(4)+H_(3)O^(+)+(H_(2)O)_(189)→HSO_(4)^(-)…H_(3)O^(+)+(H_(2)O)_(188))机制和间接(HOSO_(2)+(H_(2)O)_(191)→SO_(3)+H_(3)O^(+)…(H_(2)O)_(190)→HSO_(4)^(-)…H_(3)O^(+)+(H_(2)O)_(188))机制形成HSO_(4)^(-)…H_(3)O^(+)离子对。这两种反应机制均遵循多步反应机制,且在皮秒尺度内完成。这一发现可为解释区域大气硫酸、硫酸盐污染的成因提供新见解。Sulfuric acid is closely related to the environmental problems such as acid rain,haze formation and climate change.The traditional source of sulfuric acid is the hydrolysis of SO_(3) in the troposphere.However,this mechanism alone can not explain the high concentration of sulfuric acid.Here,we propose a novel source mechanism of sulfuric acid,the hydrolysis of HOSO_(2) at the air-water interfaces.According to classical molecular dynamics simulations,HOSO_(2) resides at the air-water interface for 62%of the time over a 150-nanosecond simulation period,revealing that the hydrolysis of HOSO_(2) at the air-water interface cannot be negligible.50 BOMD simulations showed that the hydrolysis of HOSO_(2) at the air-water interface contains two kinds of types:(i)direct(HOSO_(2)+(H_(2)O)_(191)→H_(2)SO_(4)+H_(3)O^(+)+(H_(2)O)_(189)→HSO_(4)^(-)…H_(3)O^(+)+(H_(2)O)_(188))formation mechanism and(ii)indirect formation mechanism(HOSO_(2)+(H_(2)O)_(191)→SO_(3)+H_(3)O+…(H_(2)O)_(190)→HSO_(4)^(-)…H_(3)O^(+)+(H_(2)O)_(188)).These two interfacial mechanisms follow stepwise process and are completed within the picosecond timescale.This finding will provide some new insights into the source of atmospheric sulfuric acid and sulfate pollution in the atmosphere.

关 键 词：HOSO_(2) 液滴气-液界面 反应机制 分子动力学模拟 

分 类 号：O64[理学—物理化学]