采用化学还原法制备了Ni-P非晶态催化剂,研究了制备过程中pH值及P/Ni摩尔比对催化剂结构及硝基苯催化加氢合成苯胺的影响。结果表明,在Ni-P非晶态催化剂的制备过程中,制备液初始pH值和P/Ni摩尔比是影响催化剂物化性质的主要因素。高pH值下制备的Ni-P催化剂为非晶态结构,适宜的制备液初始pH值为11.0,此时催化剂的热稳定性好,比表面积为13.7m2/g。当P/Ni摩尔比低于4时,Ni-P催化剂中Ni-P非晶态相的含量较少,适宜的P/Ni摩尔比为4。添加P/Ni摩尔比为4,在制备液pH值为11.0条件下制备0.2gNi-P非晶态催化剂,反应3h后硝基苯的转化率及苯胺的收率分别为55.2%和53.8%。
Amorphous Ni-P catalyst was prepared by chemical reduction.Effects of initial solution pH and P/Ni molar ratio on the structure of amorphous Ni-P catalyst and the catalytic hydrogenation of nitrobenzene to aniline were investigated.Results showed that the initial solution pH and P/Ni molar ratio in the preparation process have great effects on the physicochemical properties of obtained amorphous Ni-P catalyst.Ni-P catalyst with amorphous structure was formed with high initial solution pH.With initial solution pH of 11.0,the amorphous Ni-P catalyst had a surface area of 13.7 m2/g with good thermal stability.When P/Ni molar ratio was less than 4,the amorphous phase content in the catalyst was low,and the optimum P/Ni molar ratio was 4.Using 0.2 g amorphous Ni-P catalyst,which was prepared with P/Ni molar ratio of 4 and initial solution pH of 11.0,for the catalytic hydrogenation of nitrobenzene,the conversion was 55.2% and the aniline yield was 53.8% after 3 h reaction.