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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 to aniline is a green synthesis route. Its core technology is to develop an efficient hydrogenation catalyst. Amorphous Ni-Mo-P-expansive graphite (EG) catalysts were prepared by impregnation-chemical reduction method, and their catalytic performance for selective hydrogenation of nitrobenzene was investigated. The catalysts were characterized by XRD, TG, TPR and BET specific surface area. The results show that adding appropriate amount of expanded graphite into the amorphous Ni-Mo-P catalyst increases the specific surface area and pore volume of the catalyst, stabilizes the Ni-Mo-P species on the surface of the catalyst, and increases the amorphous Ni -Mo-P catalyst activity and thermal stability. Based on the mass of Ni-Mo-P, the suitable mass fraction of expanded graphite was 8%. The catalyst was reacted for 90 min at a reaction temperature of 110 ℃ and a hydrogen partial pressure of 1.8 MPa. The conversion of nitrobenzene And aniline selectivity of up to 99.5% and 99.9%.