Synthesis Of Cyclopentanone Catalyzed By γ-Al₂O₃ Supported Pd-X （X=Ni, Cu） Bimetallic Nanocatalysts

Cyclopentanone is a kind of colorless liquid, which is widely used in spices, pharmaceuticals, rubber and other industries as an important organic chemical material. In this paper, cyclopentadiene of polymers were used as raw material. Cyclopentanone were obtained by thermal depolymerization, selective hydrogenation and oxidation. γ-Al2O3 supported Pd-Ni bimetallic nanoparticles were prepared by the impregnation method and used for selective hydrogenation of cyclopentadiene to cyclopentene. Compared with traditional Pd/Al2O3 catalyst, Pd-Ni/Al2O3 showed better catalytic activity and the use of Pd was significantly reduced. With characterizations of X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy, Pd-Ni nanoparticles were identified to homogeneously distribute on the surface of the y-Al2O3 support.The catalytic activity and selectivity was assessed in view of the effects of different mass ratios of Pd and Ni elements, temperature, pressure and volume ratio of cyclopentadiene and solvent in the reaction. Among these different varieties of Pd-Ni/Al2O3 samples, the PN-1:1 (mass ratio of Pd and Ni) catalyst showed extremely high catalytic activity in an autoclave under 1.0 MPa hydrogen pressure at 35℃. The conversion of cyclopentadiene and selectivity for cyclopentene can be simultaneously up to more than 90%.γ-Al2O3 supported Pd-Cu bimetallic nanoparticles were prepared by the impregnation method and used for catalytic oxidation of cyclopentene to cyclopentanone. The detection means of XRD, XPS and TEM were also employed to characterize Pd-Cu/Al2O3, which confirmed the formation of the Pd-Cu alloy. The catalytic activity was assessed in view of the effects of different mass ratios of Pd and Cu elements, temperature, pressure and volume ratio of cyclopentene and solvent in the reaction. Among these different varieties of Pd-Cu/Al2O3 samples, the PC-5:1 (mass ratio of Pd and Cu) catalyst displayed extremely high catalytic activity in an autoclave under 2.0 MPa hydrogen pressure at 55℃. The conversion of cyclopentene was 95% and selectivity of cyclopentanone was more than 90%.