煤中脂肪族硫醚结构氧化过程机理  

Mechanism of the oxidation process of the aliphatic sulfoether structure in coal

作　　者：邓存宝[1] 戴凤威[1] 邓汉忠[2] 王钰博[3,4] 

机构地区：[1]辽宁工程技术大学安全科学与工程学院,辽宁阜新123000 [2]辽宁工程技术大学材料科学与工程学院,辽宁阜新123000 [3]辽宁工程技术大学矿业学院,辽宁阜新123000 [4]大同煤矿集团有限责任公司,山西大同037003

出　　处：《重庆大学学报（自然科学版）》2017年第8期90-98,共9页Journal of Chongqing University

基　　金：国家自然科学基金资助项目(51274112;51174108);山西省科技重大专项(20111101017)~~

摘　　要：应用Gaussian 03程序,采用密度泛函(DFT)方法,在B3LYP/6-31G(d,p)水平下研究煤中脂肪族硫醚结构(C_6H_5CH_2SCH_3)吸附O_2分子及氧化反应过程的能量变化,确定分子间氧化反应机制,为预防煤炭自燃奠定理论基础。由计算结果可知,煤中C_6H_5CH_2SCH_3结构物理吸附O_2分子形成复合物Ⅰ,形成过程是一个无势垒的过程,在热力学上是稳定的。煤中C_6H_5CH_2SCH_3结构与O2分子的相互作用距离dS-O为2.582A,经CP校正后的相互作用能为-20.60kJ/mol。分析复合物Ⅰ的电子密度变化,可确定其相互作用为范德华力,属于物理吸附。当复合物Ⅰ吸收足够的能量,将进一步发生化学反应。煤中C_6H_5CH_2SCH_3结构氧化反应共有5条反应路径,Path 4是反应的主反应路径,其产物P_3(C_6H_5CH_2SOH+CH_2O)是反应的主产物。经分析发现:煤中C_6H_5CH_2SCH_3结构易发生初步氧化,仅需12.36kJ/mol的能量,物理吸附一个O2分子释放的能量足以提供,但若要深度氧化将Path 4进行下去,需要再从外界吸收相当于物理吸附5个O_2分子释放的能量。The energy change generated from aliphatic sulfoether structure（C6 H5CH2SCH3）in coal adsorbing O_2 and oxidation was studied by using Gaussian 03 program and density functional theory（DFT）method at the B3LYP/6-31G（d,p）level,and the oxidation mechanism was analyzed to provide theoretical basis for preventing coal spontaneous combustion.The results show that the energy of complex Ⅰformed from C_6H_5CH_2SCH_3 structure in coal adsorbing O_2 is the local least,and the formation is a stable no barrier process in thermodynamics.The interaction distance dS-Obetween C_6H_5CH_2SCH_3 structure in coaland O_2 is 2.582A,and the interaction energy is-20.60kJ/mol after CP correction.Analyzing the electron density change of complex Ⅰ shows the interaction is Van der Waals forces,which belongs to physical adsorption.The complex Ⅰ will react when it absorbs enough energy.There are five reaction paths in oxidation reaction of C_6H_5CH_2SCH_3 structures in coal,Path 4is the main reaction path,and P_3（C_6H_5CH_2SOH＋CH_2O）is its principal product.The analysis shows that C_6H_5CH_2SCH_3 structure in coal is easy to be preliminarily oxidized,only 12.36kJ/mol energy is needed and the energy of physically absorbing an O_2 molecule is enough.But deep oxidation along with Path 4 needs as much as the energy of physically adsorbing 5 O_2 molecules.

关 键 词：煤 脂肪族硫醚 量子化学 吸附 氧化 

分 类 号：X43[环境科学与工程—灾害防治]