合成甲基异丙基酮和二乙基酮的Na-Pd/ZrO2-MnOx-ZnO催化剂的制备与表征

考察了催化剂组成、还原温度和反应条件对Na Pd/ZrO2 MnOx ZnO催化剂性能的影响,并用BET、XRD和NH3 TPD、CO2 TPD等技术对催化剂进行了表征。研究表明,用此方法制备的ZrO2 无晶相衍射峰,是无定型的。当n(Zr)∶n(Mn)∶n(Zn) =2 0∶(0 2~0 5)∶1 0时,既无明显的ZnO晶相衍射峰,也无明显的MnOx晶相衍射峰,ZrO2、MnOx、ZnO生成固溶体,并引起平均孔径增大和比表面积减小。ZrO2、MnOx、ZnO生成固溶体的孔径较大的催化剂具有更高的活性。x(Pd) =0 25%、x(Na) =0 29%、n(Zr)∶n(Mn)∶n(Zn) =2 0∶(0 2~0 5)∶1 0的催化剂,在常压、温度643K、原料液相空速1 0h-1条件下,甲基乙基酮的转化率达39 6%,甲基异丙基酮和二乙基酮的选择性分别为45 5%、32 2%。

Preparation and Characterization of Na-Pd/ZrO2-MnOx-ZnO Catalysts

Effects of catalyst composition,reduction temperature and reaction conditions on the catalytic performances of Na-Pd/ZrO_2-MnO_x-ZnO catalysts were studied for the synthesis of methyl isopropyl ketone and diethyl ketone.The catalysts were characterized by BET,XRD,NH_3-TPD and CO_2-TPD.The results suggested that the ZrO_2 prepared in this study is amorphous.When n(Zr)∶n(Mn)∶n(Zn)=2.0∶(0.2～0.5)∶1.0 in the catalysts,no XPD diffraction peaks of both manganese oxide and zinc oxide can be measured.It implies a solid solution of ZrO_2-MnO_x-ZnO is formed,at the mean time mean pore radius is increasing and specific surface area is decreasing.With the catalyst of 0.29% Na～0.25% Pd/ZrO_2-MnO_x-ZnO under the conditions of 1.0 h~(-1),0.1 MPa and 643 K,conversation of methyl ethyl ketone was 39.6% and selectivities for methyl isopropyl ketone and diethyl ketone were 45.5% and 32.2% respectively.