Pt / SiO ₂ Catalyst Controllable Preparation And Catalytic Selective Hydrogenation

In recent years, the supported Pt catalysts have became a hot research area becauseof its excellent catalytic performance on the hydrogenation reaction, while the low cost,the large surface area and environmental characters make the silicon dioxide supporterattracted more attention in field of industrial production. In this paper, using theindustrial SiO2and aerogel SiO2as the carrier and Pt as the active component preparedthe supported nano-platinum catalysts. Meanwhile the morphology and structure ofcatalysts were characterized by wide-angle XRD, TEM, XPS and BET techniques.These catalysts were applied to the selective hydrogenation catalytic reaction ofcinnamyl aldehyde.A series of Pt/SiO2catalysts (the loading amounts of Pt were0.5%,0.75%and1.0wt%) were prepared by using the conventional impregnation on the carrier of aerogelSiO2and characterized by a wide-angle XRD, TEM and BET techniques. The averagediameter of Pt nanoparticles of0.5%Pt/SiO2was only2.26nm, and the Pt particles werehighly dispersed on the surface of SiO2supporter. With increase the content of Pt, theparticles size have also enlarged and agglomerated, the average diameters of Ptnanoparticles of0.75%Pt/SiO2and1.0%Pt/SiO2were4.91and9.95nm respectively.The selective hydrogenation reaction of cinnamyl aldehyde was selected as the probereaction to investigate the relationship between the Pt particle size with the activity andselectivity of studied samples.A series of Pt-Cu/SiO2catalysts (the content of Pt were1.0%,2.0%,3.0%and4.0wt%) were prepared by the reduction method of metal copper and characterized bywide-angle XRD, TEM and Raman techniques. The results showed that using thecommercially available SiO2as a carrier to prepare catalysts, the size of Pt particleswere uniform and highly dispersed. The selective hydrogenation reaction of cinnamylaldehyde was selected as the probe reaction to find that, compared to Pt/SiO2material,the catalysts prepared by the reduction method of metal copper would increased theSelectivity of C=O and the conversion of cinnamic aldehyde.