Abstract:

A series of Pt-based catalysts were prepared by reverse microemulsion. The effects of synthesis parameters，such as composition of microemulsion，co-surfactant type，oil phase type，reducing agent dosage，and support type on the catalytic activity of Pt-based catalysts were studied by using m-chloronitrobenzene（m-CNB）selective hydrogenation as a probe reaction. The Pt particle and catalyst were characterized by TEM. The optimum preparation condition for Pt-based catalyst was as follows：microemulsion system of cetyltrimethylammonium bromide（CTAB）/n-butarol/cyclohexane/ H₂PtCl₆ solution with m(CTAB)∶m(n-butarol)=3∶7，m(CTAB+n-butarol)∶m(cyclohexane)=3∶7，H₂PtCl₆ solution content  of 3.6%，and N₂H₄·H₂O dosage of 100 μL. Under this condition，the Pt/γ-Al₂O₃ catalyst exhibited the highest catalytic activity in selective hydrogenation of m-CNB. The result of TEM showed that Pt particles dispersed on the surface of support uniformly.

摘要：

采用反相（W/O）微乳液法制备负载型Pt基催化剂，以间氯硝基苯（m-CNB）选择加氢反应为探针，考察微乳液组成、助表面活性剂和油相种类、还原剂用量及载体种类等制备参数对催化剂活性的影响，并对Pt粒子及催化剂进行TEM表征。结果表明：选择十六烷基三甲基溴化胺（CTAB）/正丁醇/环己烷/H₂PtCl₆溶液的W/O微乳体系，m(CTAB)∶m(正丁醇)=3∶7，m(CTAB+正丁醇)∶m(环己烷)=3∶7，H₂PtCl₆溶液含量3.6%，N₂H₄·H₂O用量100 μL时制备的Pt/γ-Al₂O₃催化剂对m-CNB选择加氢活性最高。TEM分析表明催化剂中Pt粒子均匀分散在载体上。