Cu-Fe/ZrO_2催化苯胺和CO_2合成二苯基脲反应

Synthesis of Diphenyl Urea From Aniline and CO_2 Catalyzed by Cu-Fe/ZrO_2

以Cu-Fe/ZrO2为催化剂、乙腈为溶剂,进行苯胺与CO2合成二苯基脲(DPU)反应,考察了反应条件对该反应的影响和催化剂的重复使用性能,推测了Cu-Fe/ZrO2对该反应的催化作用机理。结果表明,苯胺与CO2合成DPU反应的适宜条件为催化剂与苯胺质量比0.10、乙腈/苯胺体积比1.0、反应温度160℃、CO2初始压力1MPa、反应时间7h;在此条件下,苯胺转化率、DPU产率及其选择性分别为5.5%、5.3%和96.9%。Cu-Fe/ZrO2催化剂表面存在3类活性中心,即Cu-Fe金属位M、Lewis酸位Zrn+和Lewis碱位Zr-O-,在它们的协同作用下实现了苯胺与CO2合成DPU的反应。催化剂重复使用4次后失活,活性组分Cu的流失是其失活的主要原因。

The synthesis of diphenyl urea（DPU）was carried out with Cu-Fe/ZrO2 as heterogenous catalyst,starting from aniline and CO2 with acetonitrile as solvent.The effects of reaction conditions and the reusability of Cu-Fe/ZrO2 catalyst in the reaction of aniline and CO2 to DPU were investigated.Then the catalytic mechanism of Cu-Fe/ZrO2 in the reaction was proposed.The results showed that the suitable reaction conditions were as follows,catalyst to aniline mass ratio of0.10,acetonitrile to aniline volume ratio of 1.0,reaction temperature of 160℃,CO2 initial pressure of1 MPa and reaction time of 7h,under which the conversion of aniline,the yield and selectivity of DPU were 5.5%,5.3%and 96.9%,respectively.There existed three kinds of active sites on the surface of CuFe/ZrO2 catalyst,which were the metal site M,Lewis acid site Zrn＋and Lewis basic site Zr-O-.The cooperative catalysis of the three active sites favored the process of DPU synthesis.Cu-Fe/ZrO2 was deactivated after reused in DPU synthesis for 4cycles due to the loss of Cu active species.