Pd/C催化剂制备条件优化及其在4-氨基二苯胺生产中的应用  

Optimization of preparation conditions of Pd/C catalyst and its application in 4-aminodiphenylamine production process

作　　者：华兵[1] HUA Bing(SINOPEC Nanjing Chemical Industries Co.,Ltd.,Nanjing 210048,China)

机构地区：[1]中国石化集团南京化学工业有限公司

出　　处：《能源化工》2019年第2期33-37,共5页Energy Chemical Industry

摘　　要：采用浸渍法制备了Pd/C催化剂,考察了催化剂制备过程中加料方式、还原方法、载体种类、钯质量分数和浸渍液质量浓度对催化剂性能的影响,得到了制备Pd/C催化剂的优化工艺条件:载体为NH-03型活性炭,浸渍液质量浓度为20g/L,采用滴加的方式将PdCl2溶液加至活性炭浆液中,还原剂为(w)20%的次亚磷酸钠溶液,钯质量分数为5%。优化制备条件下制得的Pd/C催化剂用于催化加氢制备4-氨基二苯胺,表现出较好的活性,其中4-硝基二苯胺和4-亚硝基二苯胺转化率均可达到100%,4-氨基二苯胺选择性大于99%,加氢反应时间小于30min。催化剂SEM表征结果表明:自制的Pd/C催化剂表面活性炭载体凸起部分与Pd粒子粒径相当,有利于Pd粒子在活性炭表面的负载,提高Pd粒子的吸附牢固度和分散性,进而提高了Pd/C催化剂的活性。Pd/C catalyst is prepared by impregnation method.The effects of feeding method,reduction method,carrier type,the mass fraction of Pd and impregnating solution mass concentration on the performance of catalyst are investigated.The optimum process conditions for preparing Pd/C catalyst are obtained:the carrier is NH-03 activated carbon,the mass concentration of impregnating solution is 20 g/L,PdCl 2 solution is added to activated carbon slurry by dropping method,the reducing agent is(w)20%sodium hypophosphite solution and the mass fraction of palladium is 5%.The Pd/C catalyst prepared under the optimized preparation conditions has good activity in the preparation of 4-aminodiphenylamine by catalytic hydrogenation.The conversion of 4-nitrodiphenylamine and 4-nitrosodiphenylamine can reach 100%,the selectivity of 4-aminodiphenylamine is more than 99%,and the reaction time of hydrogenation is less than 30 minutes.The SEM characterization of the catalyst shows that the protruding part of the activated carbon carrier on the surface of the self-made Pd/C catalyst is similar to the particle size of Pd particles,which is beneficial to the loading of Pd particles on the surface of activated carbon,improving the adsorptive firmness and dispersion of Pd particles,and thus improving the activity of Pd/C catalyst.

关 键 词：PD/C催化剂 催化加氢 4-氨基二苯胺 制备 优化 

分 类 号：TQ426[化学工程]