电厂烟气中SO2对活性炭吸附单质铅（Pb0）的影响机理  

The effect of SO2 on adsorption of element lead （Pb0） toward activated carbon in coal-fired power plants

作　　者：高正阳[1] 刘晓硕 李昂 马传志 李祥 杨建蒙[1] GAO Zhengyang;LIU Xiaoshuo;LI Ang;MA Chuanzhi;LI Xiang;YANG Jianmeng(School of Energy and Power Engineering,North China Electric Power University,Baoding 071003)

机构地区：[1]华北电力大学能源动力与机械工程学院

出　　处：《环境科学学报》2019年第11期3732-3739,共8页Acta Scientiae Circumstantiae

基　　金：北京市自然科学基金(No.2182066);河北省自然科学基金(No.B2018502067)

摘　　要：利用密度泛函理论系统研究了SO2对活性炭吸附单质铅(Pb^0)的影响,其中,结构优化与频率计算采用B3LYP/def2-SVP级别方法和基组,单点能计算采用B3LYP/def2-TZVP级别方法和基组.同时,利用玻尔兹曼分布函数分析了SO2与Pb^0在活性炭表面的竞争吸附关系,结果表明,Pb^0在纯净活性炭上的吸附能力大于SO2.此外,本研究发现,SO2的预吸附会增强活性炭对Pb^0的吸附效果.通过静电势分布揭开了SO2促进活性炭吸附Pb^0的深层原因,结果发现,吸附SO2以后活性炭表面静电势极大值增大,极小值减小,吸附剂吸附能力因此增强.最后,利用电子密度差分图揭示出SO2改性活性炭在吸附Pb^0时,SO2对Pb^0吸附的影响可以分为直接影响和间接影响两种.In this work,we investigated the effect of SO2 molecule on adsorption of element lead(Pb^0) toward the surface of activated carbon systematically,using density functional theory.Optimization of configuration as well as frequency analysis was carried out at B3 LYP/def2-SVP level,and single point energy was calculated at B3 LYP/def2-TZVP level,respectively.The competitive adsorption analysis between SO2 and Pb^0 was performed using Boltzmann distribution function(Bdf),and the result suggested that the adsorption interaction of Pb^0 on carbonaceous materials was stronger than that of SO2.Besides,it was found that the pre-adsorption of SO2 on activated carbon could promote the adsorption of Pb^0 obviously.In addition,electrostatic potential distribution(ESP) analysis evidenced that the local maximum of ESP on activated carbon surface was enlarged and the local minimum of ESP was decreased after SO2 was adsorbed,indicating the activity of sorbent rose due to SO2 adsorption.The electronic density difference plot during Pb^0 adsorption was acquired,and it indicated SO2 molecule can impact Pb^0 adsorption directly or indirectly.

关 键 词：活性炭 单质铅 二氧化硫 密度泛函理论 

分 类 号：X701.3[环境科学与工程—环境工程]