Oxidation of Aromatic Sulfur Compounds Catalyzed by Organic Hexacyanoferrates in Ionic Liquids with a Low Concentration of H2O2 as an Oxidant
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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有机六氰基铁酸盐在离子液体中以低浓度 H2O2 为氧化剂催化芳香族硫化合物的氧化
DOI：
10.1021/ef500082y
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发表时间：
2014
期刊：
影响因子：
5.3
通讯作者：
Yin Sheng
中科院分区：
文献类型：
--
作者：
Jiang Wei;Zhu Wenshuai;Chang Yonghui;Li Huaming;Chao Yanhong;Xiong Jun;Liu Hui;Yin Sheng
合成了一系列有机六氰合铁酸盐，并将其用于离子液体中催化氧化二苯并噻吩（DBT）、苯并噻吩（BT）和4，6-二甲基二苯并噻吩（4，6-DMDBT）。以1-丁基-3-甲基咪唑铁氰化物（[C4 mim]3Fe（CN）6）为催化剂，1-丁基-3-甲基咪唑四氟硼酸盐（[C4 mim] BF 4）为萃取剂，在温和条件下，H2 O2存在下，获得了较高的催化活性.有趣的是，发现H2 O2浓度对脱硫效率有显著影响。当H2 O2浓度为30wt%时，脱硫率为76.3%，当H2 O2浓度为7.5wt%时，脱硫率可达97.9%。电子自旋共振（ESR）谱分析表明，催化氧化脱硫过程中产生了活性氧物种O2·-，气相色谱-质谱（GC-MS）分析表明，硫化物被氧化为相应的砜。考察了反应温度、反应时间、H2 O2浓度、催化剂用量、催化剂循环使用以及不同含硫化合物对反应的影响。动力学研究表明，含硫化合物的氧化反应符合准一级动力学。在最佳条件下，催化体系可循环使用4次以上，活性无明显下降。
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 H2O2under mild conditions. It was interesting to find that the concentration of H2O2had a significant influence on desulfurization efficiency. The sulfur removal was 76.3% with 30 wt % H2O2as 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•–was generated in the catalytic oxidative desulfurization process, and gas chromatography–mass spectrometry (GC–MS) 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.