【摘要】 采用乙醇溶液浸渍法制备了MgO负载的Cu2 PMo11VO40 催化剂,考察了催化剂对正己醇氧化脱氢生成正己醛的催化性能,确定了最佳反应条件.催化剂经5 0h反应后活性没有下降,生成正己醛的选择性保持在96 0 %以上.IR光谱和TPR结果表明,在反应条件下催化剂上不断有V5+从Keggin结构中移出,与Cu2 +一起作为抗衡离子存在于Keggin结构单元之外,形成缺位的Keggin型结构,使催化剂处于活化状态;Cu2 +的存在使催化剂的还原温度降低,Keggin结构之外的V5+与Cu2 +之间存在相互作用,可使催化剂活性提高更多还原

【Abstract】 The Cu₂PMo 11 VO 40 /MgO catalyst was prepared by impregnating MgO with the alcohol solutions of copper nitrate and molybdovanadophosphoric acid successively. The catalyst was used for the oxidative dehydrogenation of n -hexanol to form n -hexanal. The catalyst activity remained unchanged and the selectivity for n -hexanal was higher than 96 0% after reaction for 50 h at 280 ℃. The results of IR and TPR showed that the Cu₂PMo 11 VO 40 kept its Keggin type structure after being supported on MgO. V 5+ cations removed from the Keggin unit and presented as the counterions together with Cu 2+ cations during the reaction, which resulted in the formation of lacunar heteropolyanion. There was a synergic effect between the V 5+ and Cu 2+ cations, which was responsible for the high catalytic activity.更多还原