摘要
以金属氧化物 ZrO_2,TiO_2,γ-Al_2O_3,MnO_x,PbO,MgO,CuO 为载体和氧化还原助剂,以 NaOH 为沉淀剂制备了苯酚氧化羰基化合成碳酸二苯酯(DPC)的催化剂;考察了催化剂载体的制备方法、焙烧温度及反应温度对 DPC 收率的影响。实验结果表明,以碳酸锰热分解法制得的 MnO_x 为载体负载 Pd 制得的 Pd/MnO_x 催化剂具有良好的催化活性。对不同焙烧温度下由碳酸锰热分解法制得的 MnO_x 为载体的 Pd/MnO_x 催化剂的比表面积、晶相结构和价态进行了表征。结果表明,Pd/MnO_x 催化剂中 MnO_2是促进 Pd^0向活性 Pd^(2+)转化的有效助剂。在 Pd 质量分数0.5%、p(CO):p(O_2)=93:7、反应时间5 h、反应温度65℃的条件下,以370℃焙烧所得的 MnO_x 为载体制备的 Pd/MnO_x 催化剂的活性最高,DPC 收率达10.7%,选择性达99 1%。
Some metal oxides namely ZrO2, TiO2, γ-Al2O3, MnOx, PbO, MgO and CuO were selected as oxidation reduction cocatalysts and supports of Pd catalyst for direct synthesis of diphenyl carbonate（DPC）. NaOH was used as a precipitating agent of PdCl2 in preparation of catalyst. Highly active MnOx cocatalyst was screened out by evaluation of the catalyst. Effects of support preparation method, calcining temperature and reaction temperature on catalyst activity were also studied. The catalyst prepared by decomposing manganese carbonate showed the highest catalytic activity. Specific surface area, crystalline structure and atomic valent of the Pd catalysts supported on manganese oxide prepared at different calcining temperature were determined. The result showed that MnO2 in Pd/MnOx is an efficient cocatalyst to promote the conversion of Pd^0 to active Pd^2＋. Pd/MnOx prepared by decomposing manganese carbonate at 370 ℃ showed the highest activity. DPC yield and selectivity to DPC is 10.7 % and 99.1% respectively, when Pd loading （ mass fraction ） 0.5 %, p （ CO ） ： p （ O2 ） 93 ： 7, reaction pressure 4.5 MPa, reaction time 5 h, reaction temperature 65 ℃.
出处
《石油化工》
EI
CAS
CSCD
北大核心
2008年第7期672-676,共5页
Petrochemical Technology
基金
国家自然科学基金项目(20476083)
关键词
钯
锰氧化物
苯酚
氧化羰基化
碳酸二苯酯
催化
palladium
manganese oxide
phenol
oxidative carbonylation
diphenyl carbonate
catalysis
