摘要
以Fe(NO_3)_3和(NH_4)_6MoO_(24)为原料,采用溶胶-凝胶法制备了不同n(Fe):n(Mo)的催化剂,考察了该催化剂对对二甲苯催化氧化合成对苯二甲醛的催化性能。并应用X射线衍射、傅立叶变换红外光谱、紫外漫反射和热分析对催化剂进行了表征。结果表明,Fe对MoO_3改性能明显改善催化剂的活性,提高对苯二甲醛收率,原因是由于Fe_2(MoO_4)_3的生成。当n(Fe):n(Mo)=1:3时,催化剂活性最佳,此时对二甲苯转化率为66.8%,对苯二甲醛选择性和收率分别为37.2%和24.8%。xRD、FT-IR和DRS结果表明,当n(Fe):n(Mo)=1:3时,催化剂中有适量MoO_3存在,其催化活性最好,该催化剂能在高温维持较好的活性稳定性。
Catalysts with different Fe/Mo molar ratio were prepared by sol-gel method,with the precursor being obtained from Fe(NO_3)_3 and (NH_4)_6MoO_(24) in citric acid,characterized by XRD,FT-IR,DRS and DSC.Catalytic behaviors of the catalysts for selective oxidation of p-xylene to terephthalaldehyde (TPAL) were investigated.The results showed that modification of MoO_3 by Fe enhanced activity of the catalyst and yield of TPAL due to formation of Fe_2 (MoO_4)_ 3,with p-xylene conversion of 66.8% ,selectivity to TPAL of 37.2% and TPAL yield of 24.8% at optimum Fe/Mo molar ratio of 1:3.XRD,FT-IR and DRS results showed that there existed appropriate amount of MoO_3 at Fe/Mo molar ratio of 1:3, leading to optimum catalytic activity and high activity stability at high temperature.
出处
《工业催化》
CAS
2009年第8期51-55,共5页
Industrial Catalysis
基金
国家自然科学基金资助课题(20776031)
广州大学科研创新团队项目(广大[2008]127号)
