超重力法制备La_(0.5)Pb_(0.5)MnO_3及其在碳酸二苯酯合成中的应用

采用液液相共沉淀法在旋转填充床中合成钙钛矿型复合氧化物La0.5Pb0.5MnO3的前驱体,再经高温焙烧后制备出碳酸二苯酯合成催化剂的载体材料。考察了旋转填充床转速、反应物流量和添加分散剂PEG对La0.5Pb0.5MnO3物性的影响,通过XRD、BET、SEM、粒度分析手段对载体进行表征。结果表明,旋转填充床转速为1200r.min-1,反应物流量为80L.h-1,加入PEG10000时可制备出纯晶相的钙钛矿载体,相应的载钯(Pd占载体质量的0.5%)催化剂在氧化羰基化合成碳酸二苯酯反应中的活性最好。当反应总压为5MPa、CO/O2分压比为96:6、反应时间3h、反应温度65℃时,碳酸二苯酯收率可达13.30%。

Preparation of La0.5Pb0.5MnO3 powder by rotating packed bed and its application in synthesis of diphenyl carbonate

The precursor of perovskite-type La_0.5Pb_0.5MnO₃ oxide was prepared by co-precipitation method in rotating packed bed (RPB).The effects of rotating speed of RPB, flow rates of reactants and the addition of PEG10000 on properties of La_0.5Pb_0.5MnO₃ powder were investigated in combination with XRD, BET and SEM techniques.The results showed that the suitable conditions for preparation of precursor were as follows: rotating speed of 1200 r·min^-1, reactants flow rate of 80 L·h^-1 and PEG10000 as disperser.The corresponding La_0.5Pb_0.5MnO₃ powder obtained by calcined was used as supports for Pd- catalytic synthesis of diphenyl carbonate（DPC） and showed good performance.The yield of DPC could achieve 13.30% when reaction temperature was 65℃,p=5 MPa, p(CO)∶p(O₂)=94∶6, and reaction time 3 h.