Preparation Of Pd-ZrO 2 Catalyst And Its Effect On One-step Synthesis Of Methyl Isobutyl Ketone

The one-step process for acetone hydrogenation to MIBK is coupled the endothermic reaction and heat release reaction,which making the d ehydration steps and hydrogenation happening in one reactor. This reaction requires certain sites of acid and hydrogenation, and the strength of these two sites must be appropriate, any site too strong or too weak, will affect the product, so it’s very important to the choice of carrier. Zr O2 is the only metal oxides that has acidity,basicity,oxidizing and reducing chemical properties. It has excellent catalytic properties. Therefore, choosing Zr O2 as the carrier of one-step synthesis of methyl isobutyl ketone.This paper prepared the different structure and morphology of Zr O2,by changing the preparation technology,such as calcination temperature, zirconium sources, impregnation order and load of impregnation. And studied carrier preparation process and structure on the influence of one-step synthesis of methyl isobutyl ketone. The catalysts’ physical and chemical structure were characterized by X-ray diffraction(XRD),BET surface area, NH3-TPD, and H2-TPR. Calcination temperature, zirconium sources, impregnation order and load of impregnation had certain influence, and these influence to some extent, affected the sites of condensation and hydrogenation, showing different catalytic activity.The volume of the reaction kettle had a huge impact on this reaction. Because the volume of the reaction kettle affected hydrogen content and the effect of mixing, which directly affected the hydrogenation, condensation. By changing the volume of the reaction kettle, founding the larger reaction kettle had higher conversion of acetone and lower selectivity of MIBK, smaller reaction kettle had lower conversion of acetone and higher selectivity of MIBK.Adding Y2O3 had a great influence on carrier crystal and structure. The carrier that not adding Y2O3 present monoclinic phase after 550 ℃ calcination, the carrier of adding Y2O3 present tetragonal phase after 550 ℃ calcination. Using these two phase of the carrier prepared accordingly catalyst By physical and chemical characterization found that NH3-TPD 、 H2- TPR had certain differences. The difference of carrier crystal’ influence the carrier of acidic and distribution of the metal on the carrier to some extent, which affected the catalytic activity of the catalyst.