新型苯加氢制环己烯Ru-B/ZnO-ZrO_2催化剂的制备与表征

Preparation and Characterization of a Novel Catalyst Ru-B/ZnO-ZrO_2 for Hydrogenation of Benzene to Cyclohexene

制备了不同n(Zn)∶n(Zr)的双组分氧化物载体,并进行了各种表征。XRD、TEM结果表明ZnO-ZrO2为纳米级,N2吸附表明不同n(Zn)∶n(Zr)的载体具有相近的比表面积、孔体积和平均孔径等组织结构性质。采用化学还原法负载Ru活性组分,并对催化剂进行了XRD、DSC等表征,结果表明:Ru-B/ZnO-ZrO2催化剂中Ru-B为非晶态合金,ZrO2为四方型,Ru活性组分很好的分散于载体上。该催化剂在140℃、4 MPa氢气压力和0.2 mol/L ZnSO4溶液下进行苯加氢制环己烯反应时,环己烯最大收率可达43%。

Binary oxide supports with different Zn/Zr molar ratios were prepared,and the supports were characterized by XRD,TEM and N2 physisorption.XRD and TEM results showed that the ZnO-ZrO2 supports were nanosized.The physical properties of supports with different Zn/Zr ratios were almost the same.Ru-B/ZnO-ZrO2 catalysts were prepared by chemical reduction method,and characterized by XRD and DSC.The XRD and DSC results showed that the Ru-B/ZnO-ZrO2 catalyst consisted of an amorphous Ru-B alloy and of tetragonal ZrO2 crystallites.In the liquid-phase selective hydrogenation of benzene to cyclohexene over the as-prepared catalyst in the presence of 0.2 mol/L ZnSO4 at 140 ℃ under 4 MPa H2,a maximum cyclohexene yield of 43% was achieved.