Preparation and characterization of a plasma treated NiMgSBA-15 catalyst for methane reforming with CO2 to produce syngas

Abstract

A plasma-assisted method was employed to prepare a NiMgSBA-15 catalyst. The catalytic properties of this catalyst were tested in methane reforming with carbon dioxide. The plasma-treated catalyst exhibited a higher initial catalytic activity and a better stability than those of the untreated counterpart catalyst. To elucidate the effect of the plasma treatment, the catalysts were characterized using XRD, N₂ physisorption, XPS, TPR, CO₂-TPD, TEM, TGA, Raman and temperature-programmed hydrogenation (TPH) techniques. The results obtained confirmed that the plasma treatment of the Ni precursor had a significant impact on the surface characteristics of the active sites. The plasma treatment reduced the sizes of the Ni clusters and enhanced Ni–support interaction, which enhanced the catalytic performance. The stronger basic sites derived from plasma treatment favored the chemisorption of CO₂ and drove the coke elimination. The sintering of the metallic Ni particles did not take place during tests due to the confinement effect of the pore channels of mesoporous material. In addition, the plasma-treated catalyst showed excellent resistance to the deposition of filamentous carbon and encapsulating carbon. This was in contrast to the calcined sample, whose surface was covered by large amounts of graphitic carbon species, resulting in activity loss.