Abstract:

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.

Key words:

旋转填充床, 共沉淀, 钙钛矿型复合氧化物, 碳酸二苯酯

摘要：

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La_0.5Pb_0.5MnO₃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La_0.5Pb_0.5MnO₃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1200 r·min^-1，反应物流量为80 L·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5 MPa、CO/O₂分压比为96∶6、反应时间3 h、反应温度65℃时，碳酸二苯酯收率可达13.30%。

关键词:

旋转填充床, 共沉淀, 钙钛矿型复合氧化物, 碳酸二苯酯