中文摘要：

针对质子型离子液体[Hnmp]HCOO在加入H2O2后生成的过氧化物[Hnmp]HCOOO氧化苯并噻吩（BT）、二苯并噻吩（DBT）和4,6-二甲基二苯并噻吩（4,6-DMDBT）的氧化脱硫反应，采用密度泛函理论DFT/B3LYP-D3方法考察了这三种硫化物的反应历程。首先通过几何优化得到了[Hnmp]HCOO和[Hnmp]HCOOO的稳定结构，然后考察了[Hnmp]HCOOO氧化BT、DBT和4,6-DMDBT的反应机理，寻找可能的过渡态、中间体，计算各步反应的能量变化。结果表明，[Hnmp]HCOOO先将硫化物氧化成亚砜，然后进一步氧化成砜；在氧化过程中，DBT的反应速率是三者中最快的，与文献的实验结果一致，且H2O2/[Hnmp]HCOO体系的脱硫效果优于传统的H2O2/HCOOH体系。

英文摘要：

In this work, the oxidative desulfurization (ODS) mechanisms of benzothiophene (BT), dibenzothiophene (DBT)and 4,6-dimethyl dibenzothiophene (4,6-DMDBT) in [Hnmp]HCOO ionic liquid with H2O2 as oxidant were studied bydensity functional theory DFT/B3LYP-D3 method. Firstly, the most stable structures of [Hnmp]HCOO and[Hnmp]HCOOO were obtained by geometrical optimization. Then the reaction mechanisms between [Hnmp]HCOOO andthe three thiophene compounds were explored. The most likely transition states and intermediates were then investigated,and the energy change for each reaction step was calculated. According to the reaction mechanism, the oxidation of thethiophene compounds using peroxide [Hnmp]HCOOO had undergone processes of sulfoxide formation and sulfoneformation. The results show that the ODS reaction rate of DBT is the most rapid, which is in accordance with theexperimental results in reference; and the desulfurization efficiency of the H2O2/[Hnmp]HCOO system is higher than thatof the traditional H2O2/HCOOH system.