硝基苯在Ni-Mo-P-EG非晶态催化剂上选择加氢合成苯胺

Hydrogenation of Nitrobenzene to Synthesize Aniline over Ni-Mo-P-EG Amorphous Catalyst

由硝基苯选择加氢合成苯胺是一条绿色合成路线,其核心技术是研制高效的选择加氢催化剂。通过浸渍-化学还原法制备了非晶态Ni-Mo-P-膨胀石墨(EG)催化剂,考察了其催化硝基苯选择加氢的性能。并采用X射线衍射(XRD)、热重分析(TG)、程序升温还原(TPR)、比表面积-孔径分布测试等手段对催化剂进行了表征。研究表明,在非晶态的Ni-Mo-P催化剂中掺入适量的膨胀石墨增大了催化剂的比表面积和孔容,稳定了催化剂表面的Ni-Mo-P物种,提高了非晶态Ni-Mo-P催化剂的活性和热稳定性。以Ni-Mo-P的质量为基准,膨胀石墨的适宜添加质量分数为8%,该催化剂在反应温度为110℃、氢气分压为1.8 MPa的条件下反应90 min,硝基苯的转化率和苯胺的选择性分别可达99.5%和99.9%。

The selective hydrogenation of nitrobenzene （NB） to synthesize aniline （AN） is an environmental friendly synthesis route, and its core is the efficiently selective hydrogenation catalyst. Herein, the amorphous Ni-Mo-P-expanded graphite （EG） catalysts were prepared by impregnationchemical reduction method. Then, their catalytic performance in the selective hydrogenation was researched by the probe reaction. After that, the catalytic properties of the samples were further investigated by X-ray diffraction （ XRD ）, thermogravimetric analysis （ TG）, temperature programmed reduction（TPR）, test of specific surface area and pore size distribution, etc. The results show that appropriate addition of expanded graphite could increase the specific surface area and stabilize the Ni- Mo-P active species of the catalyst. Meanwhile, it could also increase the thermal stability and activity of the catalyst. The optimal addition of EG was 8% （ additional in the Ni-Mo-P）, with the reaction temperature of 110℃ ,hydrogen pressure of 1.8 MPa and reaction time of 90 rain, and the conversion of nitrobenzene and the selectivity of aniline reached 99.5% and 99.9% respectively.