Fe_2O_3-V_2O_5掺杂,Cr_2O_3催化间甲酚甲基化制2,3,6三甲基苯酚

为得到高效低温催化剂,在Fe2O3-V2O5复合氧化物催化剂中添加不同金属氧化物MaOb(MaOb=CeO2,CaO,ZnO,ZrO2,Cr2O3)对其进行改性,制得Fe2O3-V2O5-MaOb催化剂,并将其用于间甲酚甲基化制备2,3,6-三甲基苯酚的反应。实验结果表明,按n(Fe):n(V):n(Cr)=100.0:1.0:0.5的比例添加Cr2O3可有效改善Fe2O3-V2O5催化剂的活性,优化的Fe2O3-V2O5-Cr2O3催化剂制备条件为:焙烧温度450℃、焙烧时间4 h、沉淀剂为25%(w)氨水。采用优化条件下制备的Fe2O3-V2O5-Cr2O3催化剂进行间甲酚甲基化反应,适宜的反应条件为:反应温度330℃、进料液态空速0.53 h-1。在优化反应条件下,间甲酚转化率为99.2%,2,3,6-三甲基苯酚选择性为94.6%。

Methylation of m-Cresol to 2, 3, 6-Trimethylphenol Catalyzed by Cr2O3 Doped Fe2O3-V2O5

Metallic oxide doped Fe2O3-V2O5 catalysts,which were used in the methylation of m-cresol to 2,3,6-trimethylphenol,were prepared by the addition of CeO2,CaO,ZnO,ZrO2 or Cr2O3 to the Fe2O3-V2O5 catalyst.The results showed that Cr2O3 doping could improve the catalyst activity with the optimized ratio n(Fe):n(V):n(Cr) 100.0:1.0:0.5.The optimized catalyst preparation conditions were:calcination temperature 450 ℃,calcination time 4 h and 25%(w)NH3.H2O as the precipitant.Under the appropriate reaction conditions of reaction temperature 330 ℃ and LHSV 0.53 h-1,the conversion of m-cresol and selectivity to 2,3,6-trimethylphenol could reach 99.2% and 94.6%,respectively.The reaction temperature is lower than that of Fe2O3-V2O5 catalyst.