钯负载铁酸盐催化苯酚氧化羰基化合成碳酸二苯酯

为了将负载铁酸盐催化剂应用于磁稳定床中催化合成碳酸二苯酯,考察了焙烧温度(400～800℃)和焙烧时间(1～4h)对铁酸锰载体结构特征、磁学性质以及相应催化剂在催化苯酚氧化羰基化合成碳酸二苯酯中的催化特性的影响,采用柠檬酸络合法制备出尖晶石铁酸盐载体铁酸锰,通过沉淀法负载活性组分钯制备了钯负载铁酸锰催化剂,使用X-射线衍射(XRD)、比表面积孔径分析仪(BET)、扫描电镜(SEM)和振动样品磁强计(VSM)对其进行了相应的表征.结果显示,铁酸锰载体焙烧温度对催化剂的结构特征、磁性以及催化活性均有较大影响,而焙烧时间对其相应的影响则相对较小;其中,载体在500℃下焙烧2h,具有单一的尖晶石结构,较大的比表面积以及良好的孔结构;比饱和磁化强度可达40.2emu/g,其剩磁小于5.0emu/g,矫顽力小于15kA/m,符合磁稳定床中对于磁性固体颗粒磁学特性的要求;相应催化剂具有最大的收率5.15%.负载铁酸盐催化剂应用于磁稳定床中催化合成碳酸二苯酯的最佳工艺条件是:铁酸锰载体的焙烧温度为500℃,焙烧时间为2h.

Synthesis of diphenyl carbonate by oxidation carbonylation of phenol over Pd/MnFe2O4

To explore the application of oxidation carbonylation of phenol to diphenyl carbonate catalysized by spinel ferrite in magnetic stabilized fluidized bed, the impact of calcination temperature and calcination time on the properties of MnFe2O4, such as structural features, magnetic properties and catalytic properties of the catalyst was investigated. Spinel ferrite MnFe2O4 was prepared as a support by the citrate complex method and Pd/MnFe2O4 catalyst was prepared by the precipitation method. The samples were characterized by XRD, BET, SEM and VSM. Compared with the calcination time, the support calcination temperature has a greater influence on texture, magnetic properties and catalytic activity. Moreover, when MnFe2O4 support is calcinated for 2 h at 500℃, its saturation magnetization comes up to 40. 2 emu/g, which meets the requirements of the solid applied in magnetic stabilized fluidized bed, and yield of diphenyl carbonate is 5.15%. The best process condition is shown as follow： the support MnFe2O4 is calcined at 500℃ for 4 h.