钼基改性催化剂的制备及其催化氧化脱硫性能研究

采用自组装的方法合成了氧化硅，考察了硅源浓度、模板剂用量及陈化时间对氧化硅介孔结构的影响。以氧化硅为载体，采用等体积浸渍法制备了钼基负载型催化剂，并加入柠檬酸、硝酸镧、硝酸铈对其进行改性。在温和条件下，以双氧水为氧化剂，考察了不同改性催化剂对减压馏分油（VGO）的催化氧化脱硫性能，并优化了催化氧化脱硫条件。结果表明：氧化硅的最佳合成条件为硅源浓度0.68 mol/L、CTAB/TEOS摩尔比0.22、陈化时间2 h；催化剂脱硫活性由大到小的顺序为Ce-MoO3/SiO2＞CA-MoO3/SiO2＞MoO3/SiO2＞La-MoO3/SiO2；以Ce-MoO3/SiO2为催化剂时，最佳催化氧化脱硫条件为氧化温度70 ℃、O/S摩尔比8、氧化时间2 h、催化剂的加入量（w）15%，此条件下VGO脱硫率达到64.8%。

PREPARATION AND MODIFICATION OF Mo-BASED CATALYST AND ITS CATALYTIC OXIDATIVE DESULFURIZATION PERFORMANCE

SiO2 was synthesized through self-assembly method and the effect of different synthesis conditions on the pore structure and oxidative desulfurization were investigated including the concentration of silica source, the dosage oftemplate and the period of aging. The supported catalysts were synthesized by incipient impregnation method with the SiO2 as support, and then modified by the introduced citric acid (CA), Ce(NO3)3?6H2O and La(NO3)3?6H2O, respectively. A series of the modified catalysts were applied to catalytic oxidative desulphurization reaction to evaluate their performance with H2O2 as oxidantand then the reactionconditions on catalytic oxidative desulphurization of VGO were investigated. The results are that the best synthesis conditions of SiO2 are concentration of silica source of 0.68 mol/L, CTAB]/TEOS] of 0.22 and aging time of 2 h; The order of desulfurization performance is Ce-MoO3/SiO2＞CA-MoO3/SiO2＞MoO3/SiO2＞La-MoO3/SiO2; The desulfurization rate of VGO is 64.8% with Ce-MoO3/SiO2as catalystunder the optimal conditions (the temperature of 70 ℃,nO/nS of 8,the timeof 2 h, the dosage of catalyst of 15wt%).