Abstract: By leveraging its catalytic oxidation effect to remove dibenzothiophene (DBT) from model oil, a novel di-[EtPy]/[CoCl3] ionic liquid catalyzer was created using 1,4-dichlorobutane, pyridine, and cobalt chloride. The product was characterized by nuclear magnetic resonance (HNMR), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TG), and scanning electron microscopy (SEM-Mapping-EDS). This study constructed an extraction catalytic oxidation system (ECODS) using di-[EtPy]/[CoCl3] catalyst, ketone oxide (PMS) as oxidant, and acetonitrile as extractant to explore the catalytic activity and the removal effect of DBT in octane. The double-end structure of the double ionic liquid gave the catalyst a twofold chance of making contact with the oxidant once it was added, enhancing the release of the sulfate radical from the catalytic oxidant. Under the optimal desulfurization conditions: m(oil)=6 g, m(di-[EtPy]/[CoCl3])=0.10 g, m(acetonitrile)=1.00 g, m[PMS (20wt%)]=0.50 g, t=70 min, T=45.0℃, the removal rate of DBT in fuel oil could be as high as 96.86%. The analysis showed that the dipyridine ring of the catalyst strengthens the π bond and electrostatic interaction with DBT, and the double catalytic sites were the main reasons for the high catalytic efficiency. The desulfurization rate of di-[EtPy]/[CoCl3] catalyst after five cycles was more than 86.00%, which was mainly due to the interaction of ionic liquid and metal ions reducing the loss of catalyst. Finally, the oxidation product was identified as dibenzothiophene sulfone (DBTO2) by GC-MS, and the mechanism of the oxidation process was preliminarily discussed. The research showed that the di-[EtPy]/[CoCl3] ionic liquid as a catalyst had high catalytic activity and desulfurization performance, providing a new catalyst and process system for the industrial removal of DBT.

Key words: di-ionic liquid, oxone, extraction catalytic oxidation desulfurization technology, Oxidation mechanism, pyridine

摘要： 采用两步法制备di-[EtPy]/[CoCl3]离子液体为催化剂，并利用核磁共振波谱(HNMR)、傅里叶红外光谱仪(FT-IR)、热重分析仪(TG)和扫描电子显微镜(SEM-Mapping-EDS)等仪器对催化剂进行表征。本研究以di-[EtPy]/[CoCl3]为催化剂、过硫酸盐(PMS)为氧化剂、乙腈为萃取剂构建一套萃取催化氧化脱硫体系，对正辛烷中的二苯并噻吩(DBT)进行脱除。不仅考察了催化剂的制备，还探究了催化剂的催化性能、脱硫性能以及影响脱硫的主要因素。研究表明，在初始含硫浓度为609 mg/kg的模拟油加入量为6 g，di-[EtPy]/[CoCl3]投加量为0.10 g，PMS (20wt%)投加量为0.50 g，萃取剂乙腈投加量为1.00 g，体系反应温度45.0℃以及反应时长70 min条件下，模拟汽油的脱硫率为96.86%。di-[EtPy]/[CoCl3]循环使用5次后，脱硫率仍能达到86.00%。由于氧化产物经气相色谱-质谱联用仪(GC-MS)表征为二苯并噻吩砜(DBTO2)，本研究结合实验结果对氧化过程机理进行了分析和推测。

关键词: 双离子液体, 过硫酸氢钾, 萃取催化氧化脱硫技术, 氧化机理, 吡啶