聚乙二醇对HPMo/SiO_2结构及其催化氧化脱除二苯并噻吩性能的影响

INFLUENCE OF POLYETHYLENEGLYCOL ON HPMo/SiO_2 STRUCTURE AND ITS PERFORMACE OF OXIDATIVE REMOVAL OF DIBENZOTHIOPHENE

采用聚乙二醇(PEG6000)为模板剂,以正硅酸乙酯为前躯体,通过沉淀法制备了SiO2负载型磷钼酸(HPMo)催化剂PEG-HPMo/SiO2,并对催化剂进行了FT-IR,XRD,FE-SEM,31P-NMR表征,采用NLDFT平衡模型分析计算了催化剂的比表面积、孔径分布、总孔体积及介孔分率。考察了催化剂使用量、H2O2使用量、反应温度及反应时间对催化氧化脱硫效果的影响。研究结果表明,制备的催化剂PEG-HPMo/SiO2中含有HPMo的Keggin活性结构。对于10 mL模型油(硫质量分数为400μg/g),在催化剂用量0.05g,H2O2用量0.03mL,反应温度50℃,反应时间15 min的条件下,模型油中二苯并噻吩(DBT)的脱除率可以接近100%。催化剂在重复使用6次后,经过简单干燥处理仍有较高活性。

PEG-HPMo/SiO2 catalysts were prepared by precipitation method using PEG6000 as template and tetraethyl orthosilicate（TEOS）as silica source and characterized by Fourier transform infrared spectroscopy（FT-IR）,X-ray diffraction（XRD）,field emission scanning electron microscope（FE-SEM）and 31 P superconducting nuclear magnetic resonance spectrometer（31P-NMR）.The specific surface area,pore size distribution and mesoporous ratio were calculated via the NLDFT equilibrium model.The influence of various parameters including dosage of catalyst,dosage of H2O2,reaction temperature and reaction time on the conversion of DBT was investigated.The results show that PEGHPMo/SiO2 contains the Keggin active structures.For 10 mL model fuel（mass fraction of sulfur element is 400μg/g）,DBT in the model oil can be almost totally removed under the conditions of catalyst0.05 g,H2O20.03 mL,reaction temperature 50 ℃ and reaction time 15 min.The catalytic activity of PEG-HPMo/SiO2 is not significantly reduced after the catalyst is reused for 6times.