Characterization and Catalytic Behavior of Nano Pt/MgO Catalysts

摘要

Pt/MgO catalysts were prepared by using wet impregnation method.X-ray diffraction,transmission electron-microcopy(TEM),electron spectroscopy for chemical analysis,and temperature programmed surface reaction(TPSR)were used to characterize the calcined and used catalysts.Partial Oxidation of Methane(POM)to synthesis gas was carried out in a fixed bed micro-reactor to test the catalytic activity.TEM images revealed that Pt particles have the size of less than 10 nm,the size of the support MgO is about 50-200 nm.At 800 °C,the Pt/MgO catalyst exhibited a very high activity and stability for POM reaction.Both the conversion of methane and selectivities to CO and H2 remained almost constant up to 120 h.The dispersed Pt existed in the metallic state.The state and the dispersion of active Pt and the structure of support MgO were very stable,together with the high ability to resist carbon deposition,made the catalysts show a very high stability for POM under stoichiometric reaction conditions.