A5微孔分子筛负载V2O5催化氧化对硝基甲苯

将A₅微孔分子筛浸渍于偏钒酸铵溶液，过滤，120 ℃干燥2 h，550 ℃焙烧6 h，制备了含有V₂O₅的A5微孔分子筛催化剂。采用X射线衍射、N₂吸附-脱附和扫描电镜等进行表征，并将其用于以H₂O₂为氧化剂、乙酸酐为溶剂的对硝基甲苯催化氧化生成对硝基苯甲醇的反应。在反应温度40 ℃和反应时间4 h条件下，以质量分数35%的H₂O₂为氧化剂和V₂O₅质量分数8.5%的V₂O₅/A₅为催化剂，能够获得较好的对硝基甲苯转化率（35.54%）和较高的对硝基苯甲醇选择性(67.16%)。反应结束后，在母液中通过电感耦合等离子体原子光谱仪没有检测到V₂O₅。V₂O₅/A₅催化剂连续使用3次，对硝基甲苯转化率为34.21%，对硝基苯甲醇选择性为63.39%，催化剂活性无明显降低。

Catalytic oxidation of 4-nitrotoluene by V2O5/A5 catalyst

V2O5/A5 catalyst was prepared by impregnating A5 microporous molecular sieve in ammonium metavanadate solution,and then filtering,drying at 120 ℃ for 2 h,finally calcining at 550 ℃ for 6 h.V2O5/A5 catalyst was characterized by X-ray diffraction,N2 adsorption-desorption and scanning electron microscope,and was used in the oxidation of 4-nitrotoluene to 4-nitrobenzyl alcohol by using H2O2 as the oxidant and acetic anhydride as the solvent.The results showed that 4-nitrotoluene conversion of 35.54％and the selectivity to 4-nitrobenzyl alcohol of 67.16％ were attained under the condition as follows：reaction temperature 40 ℃,reaction time 4 h,35wt％ H2O2 as the oxidant and V2O5/A5 with V2O5 mass fraction 8.5％ as the catalyst.After reaction,V2O5 was not detected in the mother liquid by ICP.4-Nitrotoluene conversion of 34.21％ and the selectivity to 4-nitrobenzyl alcohol of 63.39％ were obtained after V2O5/A5catalyst was used for 3 times,and the catalyst activity did not decrease obviously.