Ni／ZrO2-Al2O3制备表征及催化性能的研究

本文采用浸渍沉淀法制备了不同配比的ZrO2-Al2O3复合载体。并通过浸渍法制备Ni/ZrO2-Al2O3催化剂,以苯加氢制环己烷反应为探针,考察了ZrO2与Al2O3的配比对Ni催化剂催化加氢性能的影响;采用X射线衍射(XRD)、程序升温还原(TPR)、程序升温脱附(TPD)等技术考察复合载体对Ni催化剂的体相结构、还原性能以及表面吸附性能的影响。研究结果表明,ZrO2质量分数为20%的复合载体所负载的Ni催化剂有很好的加氢活性,优于单组分载体负载的Ni催化剂;采用浸渍沉淀法制备的ZrO2-Al2O3复合载体中ZrO2以非晶态形式存在,这是由于Al2O3的存在影响了ZrO2的内部结构;该载体负载的Ni催化剂较其他催化剂更容易被还原,吸附中心数量增加。

Study on the properties of Ni/ ZrO2-Al2O3 for benzene hydrogenation

A series of ZrO2-Al2O3 composite supports with different ZrO2 content were prepared by impregnation precipitation method.Supported nickel catalysts were prepared by impregnation.The effect of the weight ratio of ZrO2 to Al2O3 on the activity of Ni catalyst for benzene hydrogenation was tested.The catalysts were characterized by X-ray diffraction(XRD),temperature-programmed reduction(TPR) and temperature-programmed desorption(TPD) of H2 and benzene to study phase structure and surface properties.The Ni catalyst supported on the composite support ZA20 containing 20% ZrO2 exhibited higher activity for benzene hydrogenation than that over the singlecomponent support.ZrO2 existed as amorphous phase in the composite oxides,which could be explained by effect of Al2O3 on the intrinsic structure of ZrO2.Ni/ ZA20 were reduced more easily and had more adsorption centers than Ni/ ZrO2 and Ni/ Al2O3,which were favorable for benzene hydrogenation.