甲烷在发烟硫酸体系中部分氧化反应的热力学研究

Study on the Thermodynamics of Methane Partial Oxidation in Oleum

对于甲烷在发烟硫酸溶液中液相部分氧化生成硫酸单甲酯的反应体系,采用密度泛函理论(DFT)进行了体系的热力学计算。在密度泛函理论B3LYP/6-31G(d)水平下结合极化连续模型(PCM),优化出了硫酸溶液中各种可能存在化合物的稳定结构,并在此基础上计算了硫酸溶液中各化合物在不同温度下的热力学性质,探讨了甲烷在发烟硫酸体系中各种可能的反应途径。计算结果表明,甲烷在发烟硫酸溶液中部分氧化生成硫酸单甲酯的反应途径是可行的,其中发烟硫酸中游离的SO3起了很重要的作用。

The thermodynamics of methane partial oxidation to methyl bisulfate in oleum was studied according to the density functional theory （DFT）. The stable structures of potential compounds in sulfuric acid were optimized by using DFT at the B3LYP / 6-31G （d） level with polarizable continuum model （PCM）. Based on these, the thermodynamic properties of potential compounds in sulfuric acid were calculated and the possible reaction paths of methane partial oxidation to methyl bisulfate were discussed. The results show that the studied reaction paths of methane partial oxidation to methyl bisulfate in oleum are feasible, and the free SO3 in oleum plays a very important role.