【摘要】 以正硅酸乙酯为硅源,利用溶胶-凝胶法制备了二氧化硅负载磷钨酸季铵盐催化剂,对催化剂进行了FTIR和XRD分析。以双氧水(30%)为氧化剂,初步评价了催化剂在催化氧化二苯并噻吩反应中的催化性能,并探讨了催化剂负载量、催化剂用量、反应温度以及反应时间等反应条件对二苯并噻吩的催化氧化反应的影响。结果表明,负载后,磷钨酸季铵盐仍具有典型的Keggin结构;含有负载磷钨酸季铵盐催化剂、30%双氧水的正己烷/乙酸的双液相氧化体系可高活性的将噻吩类含硫化合物催化氧化为砜,不同噻吩类化合物的氧化遵循4,6-二甲基二苯并噻吩>二苯并噻吩>苯并噻吩>噻吩的顺序;负载催化剂可回收多次使用。更多还原

【Abstract】 A series of silica supported quaternary ammonium phosphotungstate catalysts with different loadings were prepared by solgel method and characterized with XRD and IR methods. The catalytic activity of these catalysts in oxidation reaction of dibenzothiophenes was also evaluated,and here H2O2 was taking as oxidant. Experiments results indicated that the Keggin structure was still retained after quaternary ammonium phosphotungstate supported on silica. Dibenzothiophenes were oxidized effectively with H2O2 in the presence of these catalysts in the n-hexane/AcOH biphasic system to give their corresponding sulfones as products. The oxidative reactivity of the sulfur compounds was in the order of 4,6-dimethyl dibenzothiophene>dibenzothiophene>benzothiophene>thiophene. The catalyst could be reused several times.更多还原