Selective hydrogenation of chloro- nitrobenzene to chloroaniline in supercritical carbon dioxide over Ni/TiO2: Significance of molecular interactions
Selective hydrogenation of chloro- nitrobenzene to chloroaniline in supercritical carbon dioxide over Ni/TiO2: Significance of molecular interactions
复制标题
Ni/TiO2 上超临界二氧化碳中氯硝基苯选择性加氢生成氯苯胺：分子相互作用的意义
DOI：
10.1016/j.jcat.2009.10.024
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
M. Arai
中科院分区：
文献类型：
--
作者：
X. Meng;H. Cheng;S. Fujita;Y. Hao;Y.Shang;Y. Yu;S. Cai;F. Zhao;M. Arai
研究了Ni/TiO 2催化剂在35°C超临界CO2、乙醇和正己烷中对氯代硝基苯的催化加氢反应。反应速率顺序为scCO 2>正己烷>乙醇。在scCO_2中，在9- 100%转化率范围内，Ni/TiO_2催化剂对氯代苯胺和苯胺的选择性分别为97-99.5%和<1%。在乙醇和正己烷中，Ni/TiO 2催化剂对氯代苯胺的选择性不高。采用原位高压傅里叶变换红外光谱法研究了CO2与氯代硝基苯、氯代亚硝基苯和N-氯苯羟胺的分子相互作用。分子间的相互作用改变了每种物质的反应性，从而改变了反应速率和选择性。讨论了Cl取代基对CO2与这些反应物种相互作用模式的影响。提出了在超临界CO2中Ni/TiO 2催化剂上氯代硝基苯加氢反应的可能途径。
The hydrogenation of chloronitrobenzene to chloroaniline was investigated over Ni/TiO2at 35°C in supercritical CO2(scCO2), ethanol, and n-hexane. The reaction rate followed the order of scCO2>n-hexane>ethanol. In scCO2, the selectivity to chloroaniline and to aniline over Ni/TiO2were 97–99.5% and <1%, respectively, in the conversion range of 9–100%. The high chemoselectivity to chloroaniline cannot be achieved over Ni/TiO2in ethanol and n-hexane. In situ high-pressure Fourier transform infrared measurements were made to study the molecular interactions of CO2with the following reactant and reaction intermediates: chloronitrobenzene, chloronitrosobenzene, and N-chlorophenylhydroxylamine. The molecular interaction modifies the reactivity of each species and accordingly the reaction rate and the selectivity. The influence of Cl substituent on the interaction modes of CO2with these reacting species is discussed. Possible reaction pathways for the hydrogenation of chloronitrobenzene in scCO2over Ni/TiO2are also proposed.