载体焙烧温度对Pd/Al_2O_3催化剂催化6-氯-3-硝基甲苯-4-磺酸液相加氢合成CLT酸的催化性能影响  

Influence of support calcination temperature on the performance of Pd/Al_2O_3 catalyst used in liquid-phase catalytic hydrogenation of 6-chloro-3-nitrotoluene-4-sulfonic acid

作　　者：徐乐[1] 华达银[1] 周生虎[2] 于洪波[2] 

机构地区：[1]宁波大学理学院,浙江宁波315211 [2]中国科学院宁波材料技术与工程研究所,浙江宁波315201

出　　处：《化学研究与应用》2014年第2期187-193,共7页Chemical Research and Application

摘　　要：以不同焙烧温度得到的氧化铝为载体,采用浸渍法制得负载型Pd/Al_2O_3催化剂,并将该催化剂应用于6-氯-3-硝基甲苯-4-磺酸液相加氢合成2-氨基-4-甲基-5-氯苯磺酸的反应中,结果表明,载体的焙烧温度为500℃,反应温度为100℃,反应压力为3 MPa,反应时间为2 h,Pd负载量为0.2%,催化剂用量为2 g时,6-氯-3-硝基甲苯-4-磺酸转化率最高,转化率为95.4%。此外,考察了不同脱氯抑制剂对Pd/Al_2O_3催化剂性能和脱氯反应的影响,发现在100℃时,吗啡啉能够有效抑制脱氯副反应的发生。通过XRD、BET、ICP技术对催化剂的物相组成、比表面积和贵金属含量进行了表征,发现Pd高度分散在γ-Al_2O_3载体上。The Al2O3 was calcined at different temperatures and then used as a support to prepare Pd /Al2O3 catalysts.Supported Pd/Al2O3 catalysts were prepared by incipient-wetness impregnation method and applied in liquid phase hydrogenation of 6-chloro-3-nitrotoluene-4-sulfonic acid to produce 5-amino-2-chlorotoluene-4-sulphonic acid.The results showed that the highest 6-chloro-3-nitrotoluene-4-sulfonic acid conversion of 95.4%was achieved over the 0.2 wt%Pd/Al2O3 catalyst,when the support was calcined at 500℃ under the reaction condition of the present study.（T=100℃,P=3 MPa,t=2h,catalyst dosage：2g）.In addition,the effects of different dechlorination were also investigated.It was found that dechlorination as the side reaction could be effectively in-hibited by morpholine at the reaction temperature of 100℃.The crystalline phase,BET surface area and Pd particle size of Pd/Al2O3 catalyst were characterized by XRD ,BET and TEM techniques and found that Pd was highly dispersed over the γ-Al2O3 sup-port.

关 键 词：载体焙烧温度 脱氯 PD Al2O3 催化剂 液相加氢 CLT酸 

分 类 号：O614.3[理学—无机化学]