摘要
由于煤氧化反应的初始阶段就是煤吸附O2的过程,可通过抑制O2的吸附来抑制煤的氧化自燃。应用Gaussian 03程序,采用密度泛函(DFT)方法,在B3LYP/6-31G(d,p)水平下研究分析Zn2+与煤中α位硫酚结构的作用机理,并以活化能作为指标表征Zn2+抑控煤中α位硫酚结构氧化的效果。由计算结果可知,α-萘硫酚结构中S原子LP(2)轨道上的孤对电子向Zn的LP*(6)空轨道转移,通过sp杂化形成σZn-S配位键,配位键的二阶稳定化能为266.60 k J/mol。当α-萘硫酚结构氧化时,首先与O2发生物理吸附形成复合物ComplexⅠ并释放20.12 k J/mol的能量,然后复合物ComplexⅠ的分子间发生化学作用,导致O2分子被化学吸附在—SH基上,所需活化能Ea=62.71k J/mol。[Zn SH8C10]2+配合物物理吸附O2释放的能量减少了14.92 k J/mol,且形成化学吸附所需的活化能增加了47.62 k J/mol,Zn2+对煤中α位硫酚氧化具有明显的控制作用。
The oxidation and spontaneous combustion of coal could be controlled by restraining the O2 adsorption of coal,because the initial stage of coal oxidation is the process of adsorbing O2 by coal. Using the Gaussian 03 program,the mechanism of interaction of Zn2 +and α-thiophenol structure in coal is studied by using density functional theory( DFT) method at the B3LYP/6-31G( d,p) level. Then the restraining oxidation effect of Zn2 +on α-thiophenol structure in coal is characterized by activation energy to provide a base for studying the technology of inhibition coal spontaneous combustion. The results show that the lone pair electrons of S atom on α-naphthalene thiol structure are transferred from the LP( 2) orbital to the unoccupied orbital LP*( 6) of Zn2 +,and σZn-Scoordination bond is formed by sp hybridization. The second order energy is 266. 60 k J / mol. When α-naphthalene thiol structure is being oxidized,the first step is that O2 is adsorbed physically onto it to form complex I,and release heat 20. 12 k J / mol. The second step is that O2 is adsorbed chemically onto the—SH group by chemical action. The activation energy of the process is Ea=62. 71 k J / mol. The heat released by[Zn SH8C10]2 +coordination complex physical adsorbing O2 decreases 14. 92 k J /mol,and the activation energy increases 47. 62 k J / mol. The study concludes that the inhibition effect of Zn2 +on α-thiophenol structure in coal is particularly noticeable.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2015年第9期2117-2123,共7页
Journal of China Coal Society
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资助项目(20111101017)
关键词
煤
α位硫酚
量子化学
阻化
吸附
活化能
coal
α-thiophenol
quantum chemistry
inhibition
adsorption
activation energy
