MOF-199固载过氧化磷钨酸盐催化剂的制备及其在柴油脱硫中的应用

采用简易的原位合成法合成了过氧化磷钨酸盐(TBA)₃PW₄封装于MOF-199孔道内的固载型催化剂(TBA)₃PW₄@MOF-199，借助电感耦合等离子体(ICP)、傅里叶红外光谱(FT-IR)、X射线衍射(XRD)、热重分析(TG)、场发射扫描电子显微镜(SEM)及N₂吸附-脱附等温曲线(BET)等分析手段对催化剂样品(TBA)₃PW₄@MOF-199的组成、稳定性及形貌进行了表征。采用含苯并噻吩(BT)、二苯并噻吩(DBT)、4-甲基二苯并噻吩(4-MDBT)和4,6-二甲基二苯并噻吩(4,6-DMDBT) 4种硫源的多组分模拟柴油与萃取剂组成的液-液双相系统，以双氧水为氧化剂，对催化剂的脱硫活性进行了探究，并探讨了催化剂用量、氧化剂用量及反应温度对脱硫效率的影响。结果表明：在最佳反应条件(反应温度70 ℃、催化剂(TBA)₃PW₄@MOF-199用量40 mg、H₂O₂用量0.26 mmol、模拟柴油体积0.75 mL及萃取剂［Bmim］PF₆体积0.75 mL)下，催化剂(TBA)₃PW₄@MOF-199的脱硫效率可以在80 min内达到99.9%，同时重复使用8次，脱硫效率仍保持在91%以上。该催化剂优异的催化脱硫活性及稳定性使其在工业应用上具有一定的前景。

Preparation of MOF-199 Supported Peroxophosphotungstate Catalyst and Its Application in Diesel Desulfurization

The supported catalyst (TBA)₃PW₄@MOF-199 was synthesized using a simple in-situ synthesis method through encapsulating peroxophosphotungstate (TBA)₃PW₄ in the pore of MOF-199. The composition, stability and morphology of the catalyst sample (TBA)₃PW₄@MOF-199 were characterized by inductively coupled plasma (ICP), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TG), scanning electron microscope (SEM) and N₂ adsorption-desorption isotherm (BET). Then, a liquid-liquid two-phase system consisting of a multi-component simulated diesel and an extractant was used to explore the desulfurization activity of the catalyst with hydrogen peroxide as oxidant, and the aforesaid simulated diesel contains four sulfur sources including benzothiophene (BT), dibenzothiophene (DBT), 4-methyldibenzothiophene (4-MDBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). Moreover, the effects of catalyst amount, oxidant amount and reaction temperature on desulfurization efficiency were also discussed. The results show that the desulfurization efficiency of catalyst (TBA)₃PW₄@MOF-199 can reach 99.9% within 80 min under the optimal reaction conditions (reaction temperature 70 ℃; catalyst dosage 40 mg; H₂O₂ dosage 0.26 mmol; model diesel volume 0.75 mL; ［Bmim］PF₆ volume 0.75 mL), and the desulfurization efficiency remains above 91% after repeated use for 8 times. The excellent desulfurization activity and stability of the catalyst endow it with a great prospect in industrial application.