Abstract: Pt/γ-Al2O3 catalysts promoted by K2SO4 were prepared by the impregnation method.Pt-K/γ-Al2O3 catalysts with different Pt distributions could be prepared by adding different HCl contents to the impregnation solution and were used for preparing o-phenylphenol(OPP)from o-cyclohexenylcyclohexanone(Dimer)dehydrogenation.These catalysts were characterized by XRD，H2-TPR，BET and EPMA.The results showed that the interaction of Pt species with support，the structure of the catalyst and Pt distribution were modified by adding different HCl contents to the impregnation solution.The catalyst with 0.50％HCl concentration of the impregnation solution had the largest BET surface areas optimum Pt depth and weaker interaction between Pt and support.The residence time of intermediate products and OPP on the catalyst surface were adjusted，then the formation of byproducts was prohibited and the selectivity of OPP was obviously improved.The conversion of o-cyclohexenylcyclohexanone reached 100% and selectivity of o-phenylphenol were more than 90% at 0.12 g·g-1·h-1 of LHSV and 33 ml·g-1·h-1 H2 space velocity，and 380℃.

Key words: o-phenylphenol；Pt/&gamma, -Al₂O₃ catalyst；Pt distribution

摘要： 采用分布浸渍法制备了以Pt为活性组分，K₂SO₄为助剂的Pt-K/γ-Al₂O₃催化剂，通过调节浸渍液中HCl浓度改变活性组分Pt在载体中的分布并用于环己烯基环己酮(Dimer)脱氢合成邻苯基苯酚(OPP)，并利用比表面积(BET)、X射线衍射(XRD)、H₂程序升温还原(H2-TPR)和电子探针微量分析(EPMA)等手段对催化剂进行了表征。结果表明，通过调节浸渍液中HCl浓度的方法可有效调节催化剂的结构性质，活性组分与γ-Al₂O₃载体之间的相互作用以及Pt在载体上的分布。当浸渍液中HCl浓度为0.50％时，催化剂存在较高的比表面积，Pt在载体上存在最适宜的浸渍深度以及较弱的与载体之间的相互作用，从而调整了中间产物、OPP在催化剂表面的停留时间，抑制了副反应，可显著提高生成OPP的选择性。在液相空速LHSV 0.12 g·g-1·h-1、H2空速33 ml·g-1·h-1、温度380℃的反应条件下，环己烯基环己酮转化率为100%，OPP选择性达90%以上。

关键词: 邻苯基苯酚；Pt/&gamma, -Al₂O₃催化剂；Pt分布