Oxidation of Aromatic Sulfur Compounds Catalyzed by Organic Hexacyanoferrates in Ionic Liquids with a Low Concentration of H2O2 as an Oxidant

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• 作者：Wei Jiang ; Wenshuai Zhu ; Yonghui Chang ; Huaming Li ; Yanhong Chao ; Jun Xiong ; Hui Liu ; Sheng Yin
• 刊名：Energy & Fuels
• 出版年：2014
• 出版时间：April 17, 2014
• 年：2014
• 卷：28
• 期：4
• 页码：2754-2760
• 全文大小：375K
• 年卷期：v.28,no.4(April 17, 2014)
• ISSN：1520-5029

文摘

A series of organic hexacyanoferrates were synthesized and employed as catalysts in ionic liquids (ILs) for catalytic oxidation of dibenzothiophene (DBT), benzothiophene (BT), and 4,6-dimethyldibenzothiophene (4,6-DMDBT). High activity was achieved using 1-butyl-3-methylimidazolium hexacyanoferrate ([C₄mim]₃Fe(CN)₆) as a catalyst and 1-butyl-3-methylimidazolium tetrafluoroborate ([C₄mim]BF₄) as an extractant in the presence of H₂O₂ under mild conditions. It was interesting to find that the concentration of H₂O₂ had a significant influence on desulfurization efficiency. The sulfur removal was 76.3% with 30 wt % H₂O₂ as an oxidant, while it could reach 97.9% with 7.5 wt % H₂O₂. Electron spin resonance (ESR) spectroscopy measurements gave the evidence that the active oxygen species O₂^{鈥?/sup>鈥?sup>鈥?/sup> was generated in the catalytic oxidative desulfurization process, and gas chromatography鈥搈ass spectrometry (GC鈥揗S) analysis indicated that the sulfur compounds were oxidized to the corresponding sulfones. The influence factors, such as reaction temperature, time, concentration, and dosage of H₂O₂, amount of catalyst, catalytic system recycling, and different sulfur-containing compounds, were investigated. The kinetic investigations showed that oxidation of sulfur compounds presented a pseudo-first-order kinetic. Under the optimal conditions, the catalytic system could be recycled at least 4 times without a remarkable decrease in activity.}