| p-Aminophenol(PAP) is an important raw material and organic intermediate, and it is widely used in medicine, dyestuff, rubber, feed, petroleum and photography, etc. At present the one-step synthesis of p-Aminophenol through catalytic hydrogenation of nitrobenzene(NB) is a widely used process. However, in the process the strong causticity and the large amount of sewage was caused by H2SO4 during the production. In order to overcome the shortcomings, Pt-acidic ionic liquid(IL) bifunctional catalyst was prepared and used as catalyst, which made the process more environmental friendly.A new acidic ionic liquid, N,N,N-trimethyl-N-sulfonic butyl hydrogen sulfate ([HSO3-b-N(CH3)3]HSO4), was prepared and its structure was characterized.Pt/SiO2+([HSO3-b-N(CH3)3]HSO4) catalytic system was set up. The influence of reaction conditions, such as amount of catalyst, IL mass concentration, H2 pressure, reaction temperature, reaction time, and etc, was investigated. The suitable reaction conditions were as follows: Pt/SiO2 amount, 5wt% of NB; IL mass concentration, 22.5%; H2 pressure, 0.4MPa; reaction temperature, 85℃; reaction time, 4h. When deioned water was used as the reaction solvent, and cetyltrimethyl ammonium bromide (CTAB) as the surface active agent, NB conversion and selectivity of PAP were 96.5% and 70.3%, respectively. When dimethyl sulphoxide (DMSO) was the deactivator, NB conversion and selectivity of PAP were 96.6% and 81.4%, respectively.Pt-[SO3H-bmim]HSO4/SiO2 bifunction catalyst was prepared. Effect of preparation methods on catalytic activity was studied. The catalyst prepared by successive impregnation showed better activity than that of co-impregnation. When Pt-IL bifunction catalyst was prepared in Ethanol/H2O, under the suitable condition, NB conversion and selectivity of PAP were 68.6% and 60.4%, respectively.
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