Pt/A12O3 catalyst was prepared from CTAB/butarol/cyclohexane/H2PtCl6 microemulsion,with hydrazine as reductant and A12O3 as support. The effect of composition of microemulsion on the activity for selective hydrogenation over Pt/A12O3 catalysts was studied by using o-chloronitrobenzene selective hydrogenation as a probe reaction. The support and catalyst were characterized by XRD,XPS, IR, TEM and EDS. The results showed that the Pt/Al2O3 catalyst made from the microemulsion with CTAB: butarol: cyclohexane mass ratio of 9: 21: 70 and H2PtCl6 concentration of 3.6％ exhibited the highest activity in selective hydrogenation of o-CNB. Pt particle size was about 5 nm, and the electronic effect between Pt particle and carrier was not significant. It was also found that Pt/A12O3 catalyst also exhibited higher activity for the hydrogenation of rn-chloronitrobenzene and p-chloronitrobenzene with different substituted positions.%采用十六烷基三甲基溴化铵(CTAB)/正丁醇/环己烷/H2PtCl6溶液的微乳体系,以N2H4-H2O为还原剂,Al2O3为载体制备Pt/Al2O3催化剂.以邻氟硝基苯(o-CNB)选择加氢反应为探针,考察微乳液组成对Pt/Al2O3催化剂选择加氢活性的影响.运用XRD、XPS、IR、TEM和EDS对载体和催化剂进行表征.结果表明,微乳体系中CTAB:正丁醇:环己烷质量比9:21:70,3.6%H2PtCl6溶液中制备的Pt/Al2O3催化剂的o-CNB选择加氢活性最高.Pt粒子粒径5 nm左右,与载体之间没有明显的电子效应.对于取代位置不同的间、对氯硝基苯(m-CNB、p-CNB)加氢,Pt/Al2O3催化剂也表现出较高的催化活性.
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