固定床选择性加氢反应一般要求催化剂具有良好的机械强度、较适宜的比表面积和孔容、活性组分高度分散等。为克服钯/碳纳米管（Pd/CNTs）催化剂成型性和强度不足的问题,将自产CNTs提纯后与氧化铝制成复合载体（CNTs-Al₂O₃）。表征结果显示,复合载体中CNTs与氧化铝混合均匀,CNTs保留了原有的管状结构,碳管的端口呈打开状态。对比实验结果表明,添加5%~10%CNTs（以质量分数计）的复合载体比单纯氧化铝载体负载乙酸钯后制成的催化剂活性更强。与盐酸和乙酸相比,以有机酸柠檬酸和乙二胺四乙酸作为钯的酸性络合剂时,更能减少载体比表面积和孔容的损失,活性组分在载体表面的分散性更好。在优选出的催化剂体系下,当反应温度取90~110 ℃、氢气压力取1.2~1.6 MPa条件时,可以获得更高的目标产物选择性和收率。

Selective hydrogenation on fixed bed generally needs that the catalysts has good mechanical strength,appropriate specific surface area and pore volume,high dispersion of active components,etc.In order to overcome the problem of insuffi-cient formability and strength of Pd/CNTs catalyst,self-produced CNTs were purified and then combined with alumina to form composite carrier（CNTs-Al₂O₃）.The characterization results showed that CNTs were mixed well with Al₂O₃ in composite carri-er,the original tubular structure of CNTs was retained and the ports of CNTs were open.Contrast experiments showed that cat-alysts using composite carrier with adding 5%~10% CNTs（calculate as mass fraction） were more active than that catalyst us-ing Al₂O₃ alone after supported palladium acetate.Compared with HCl and HAc,the carrier had lower loss rates of specific surface area and pore volume,the dispersion of active components on the surface of carrier was better when CA and EDTA used as acidic complexing solvents for Pd.The selectivity and yield of target product could be higher when the reaction tem-perature was 90~110 ℃ and the hydrogen pressure was 1.2~1.6 MPa under the preferred catalyst system.