研究了Ni/膨润土催化剂的制备方法与催化剂的热分析(TG-DTA)和氢程序升温还原(H2-TPR)分析,并将其应用于硝基苯气-固相催化加氢合成苯胺过程中。结果表明,Ni/膨润土催化剂在300℃,常压下进行硝基苯催化加氢为苯胺反应,硝基苯的转化率在6 h内均能达到99%以上,苯胺的收率达到85%以上。热分析表明,经350℃焙烧2 h后可获得的催化剂的活性成分为Ni O;H2-TPR分析表明,催化剂上的Ni O被还原为Ni金属而起催化作用。对催化剂的活性测试部分进行了改进,改进后的气-固相催化加氢实验在固定床反应器中进行,相比液相加压反应,改进后的实验安全性更高,更加直观,且易于理解与操作。
The catalytic hydrogenation of nitrobenzene is the main method to produce aniline in industry. The preparation method,the thermal analysis( TG-DTA) and the H2 temperature programmed reduction( H2-TPR) of Ni /bentonite catalyst were studied in the present work,and the Ni / bentonite catalyst was applied in the hydrogenation of nitrobenzene to aniline in a gas-solid reaction. The results showed that the conversion of nitrobenzene was more than99% and the yield of aniline was more than 85% when Ni / bentonite was used as catalyst in the hydrogenation of nitrobenzene to aniline reaction at 300℃ and atmospheric pressure in a gas-solid reactor during 6 h. TG-DTA results showed that the Ni O was obtained after calcined at 350℃ for 2 h,and the H2-TPR results showed that Ni O was reduced to metallic Ni,which was the active component in the hydrogenation. The activity test experiment was improved to a gassolid reactor,and the gas-solid catalytic hydrogenation was more safety,more intuitive,and much easier to understand and operate compared with the liquid reaction.