Insight into the Role of Additives in Catalytic Synthesis of Cyclohexylamine from Nitrobenzene,Chinese Journal of Chemistry

当前位置： X-MOL 学术 › Chin. J. Chem. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Insight into the Role of Additives in Catalytic Synthesis of Cyclohexylamine from Nitrobenzene
Chinese Journal of Chemistry ( IF 5.5 ) Pub Date : 2018-10-24 , DOI: 10.1002/cjoc.201800380
Xuefeng Li ₁ , Zhe Wang ₁ , Shanjun Mao ₁ , Yiqing Chen ₁ , Minghui Tang ₁ , Haoran Li ₁ , Yong Wang ₁

Affiliation

Cyclohexylamine is a versatile intermediate in various chemical industries, which can be expediently synthesized via hydrogenation of aniline or nitrobenzene. However, such processes always suffer from side reactions. Many reports have found that specific additives can suppress the formation of side products, but the mechanism is still not clear. In this work, results suggest that it is the hydroxide ion of alkali metal hydroxides, rather than the cations, which plays a key role in suppressing the side reactions on supported Ru‐based catalysts. With the assistance of LiOH, the selectivity toward cyclohexylamine increased from 85.4% to 100%. Side products, such as dicyclohexylamine, cyclohexanol and N‐isopropyl cyclohexylamine, could no longer be detected. Theoretical calculations further disclosed that addition of alkali metal hydroxides inhibited the dissociation of enamine and decreased the adsorption energy of cyclohexylamine, which might be the reasons for a better selectivity. However, the addition of alkali metal hydroxides reduced the activity of nitrobenzene hydrogenation by unfolding the condensation reaction route. To recover or even further enhance the catalytic performance, a second metal component was introduced and the resultant RuNi/AC exhibited a significant improvement in activity compared with Ru/AC.

中文翻译：

洞察添加剂在硝基苯催化合成环己胺中的作用

环己胺是多种化学工业中的通用中间体，可以方便地通过苯胺或硝基苯的加氢合成。然而，这样的过程总是遭受副反应。许多报告发现特定的添加剂可以抑制副产物的形成，但机理尚不清楚。在这项工作中，结果表明，碱金属氢氧化物的氢氧根离子而不是阳离子在抑制负载型Ru基催化剂上的副反应中起着关键作用。在LiOH的帮助下，对环己胺的选择性从85.4％增加到100％。副产物，例如二环己胺，环己醇和N异丙基环己胺不再能被检测到。理论计算进一步公开了添加碱金属氢氧化物抑制了烯胺的离解并降低了环己胺的吸附能，这可能是选择性更高的原因。然而，碱金属氢氧化物的添加通过展开缩合反应路线而降低了硝基苯氢化的活性。为了恢复或什至进一步增强催化性能，引入了第二金属组分，并且与Ru / AC相比，所得RuNi / AC表现出显着的活性改善。

更新日期：2018-10-24

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南