Study on Methane Conversion to Synthesis Gas Over Nano Pt/MgO Catalysts: I. Characterization of Pt-II Catalysts

摘要

Nanometer Pt/MgO (Pt-II) catalysts with different Pt loading were prepared by using impregnation method. BET textural analysis, X-ray diffraction (XRD), DTA thermal analysis, temperature pro-grammed reduction (TPR), CO chemisorption, and Transmission Electron Microcopy (TEM) were used to characterize the catalysts. Methane decomposition reaction was carried out to test the cat-alytic activity. The results revealed that the loading of Pt has a big influence on the texture and surface property. The dispersed Pt is in metallic state and is very stable when the catalysts were calcined at 473 K or higher temperature. The particle size of dispersed Pt is less than 2 nm. The calcination temperature influences the phase composition of the support, the phase transformation from Mg(OH)_2 to MgO finishes at 573 K, and the agglomeration of MgO particles takes place during the higher temperature calcination. The catalysts have high activity for methane decomposition, and the more the Pt content, the higher the activity.