羟基对煤中桥键活性官能团氧化反应特性的影响  

Effect of hydroxyl group on oxidation reaction characteristics of bridged functional groups in coal

作　　者：贾廷贵 殷悦 曲国娜 强倩 JIA Tinggui;YIN Yue;QU Guona;QIANG Qian(Institute of Mining and Coal,Inner Mongolia University of Science and Technology,Baotou 014010,Inner Mongolia,China)

机构地区：[1]内蒙古科技大学矿业与煤炭学院,内蒙古包头014010

出　　处：《安全与环境学报》2023年第10期3575-3583,共9页Journal of Safety and Environment

基　　金：内蒙古自治区自然科学基金项目(2022LHMS05019,2022LHMS05020);内蒙古自治区高等学校科学研究重点项目(NJZZ21025)。

摘　　要：羟基(—OH)是影响煤自燃发展的关键因素之一。为进一步了解羟基对煤自燃过程的影响,通过Gaussian软件构建出苯基与桥键类活性基团—CH_(2)—、—CH_(2)O—、—CHOHCH_(2)—分别相连以及—OH处于活性基团邻位的共6种模型,采用B3LYP方法优化模型结构、并计算其频率,得到6种模型的静电势、前线轨道能隙、表面电子云分布、焓变及吉布斯自由能变化值,分析这3种桥键类活性基团的反应活性以及羟基对其氧化反应性质的影响。结果表明:3种活性基团的反应活性由大到小依次为—CH_(2)O—、—CHOHCH_(2)—、—CH_(2)—,羟基的加入并未改变其反应活性顺序,但提高了它们各自的反应活性;羟基处于桥键类活性基团邻位会提高桥键活性基团的亲核反应能力,削弱其亲电反应能力;3种活性基团的LUMO成键能力从强到弱依次为—CH_(2)—、—CHOHCH_(2)—、—CH_(2)O—,活性基团与氧气复合的难易程度与其LUMO成键能力有关,而与反应活性无关,LUMO成键能力越强,越容易发生煤氧复合。羟基对3种桥键类活性基团与氧气的复合反应过程、过氧化物的分解反应过程均产生一定影响。Hydroxyl is one of the key factors in the development of coal spontaneous combustion.To further explore the effect of hydroxyl on the coal spontaneous combustion process,the bridge bond active groups—CH_(2)—,—CH_(2) O—,—CHOHCH_(2)—and—OH were selected as the research objects to establish a total of six simple models in which phenyl was connected to three active groups and hydroxyl was in the adjacent position of active groups.Based on the Density Functional Theory(DFT)and the 6311G(d,p)basis set,structural optimization and frequency calculation were conducted on the model by using the B3LYP method.The electrostatic potential,frontier orbital energy gap,surface electron cloud distribution,enthalpy change,and Gibbs free energy change of the six simple models were quantitatively obtained.The reactivity of three active groups and the effect of hydroxyl on the oxidation reaction properties were analyzed from many aspects.The results show that the reactivities of the three active groups from large to small is—CH_(2)O—,—CHOHCH_(2)—,—CH_(2)—.The addition of—OH fails to change the order of reactivity,but it strengthens their respective reactivities.The hydroxyl at the adjacent position of active groups can improve the nucleophilic reaction ability and weaken the electrophilic reaction ability of bridge bond active groups.In addition,The Lowest Unoccupied Molecular Orbital(LUMO)bonding capacity of the three active groups from large to small is—CH_(2)—,—CHOHCH_(2)—,—CH_(2) O—,the degree of difficulty in the combination between active groups and oxygen is related to the LUMO bonding ability,but it has nothing to do with the reaction activity.The stronger the LUMO bonding capability is,the more easily the coal-oxygen combination occurs.The values ofΔH andΔG of the active groups—CH_(2) O—and—CHOHCH_(2)—increase after the addition of—OH,while for—CH_(2)—,there is no obvious change.The Hydroxyl group has a certain influence on the complex reaction process of three kinds of

关 键 词：安全工程 煤自燃 活性基团 反应活性 氧化反应 量子化学 

分 类 号：X936[环境科学与工程—安全科学]