Catalytic evaluation of nickel nanoparticles in methane steam reforming

Abstract

Development of a highly efficient and coke-resistant, nickel nanoparticles (Ni.NPs) based catalyst in the steam reformation reaction of methane is reported. The catalyst was prepared by dispersing Ni-nanoparticles over silica functionalized alumina support. The synthesized samples were characterized by a combination of analytical techniques of X-ray diffraction (XRD), nitrogen physisorption (BET surface area), X-ray photoelectron spectroscopy (XPS), temperature programmed reduction (H2-TPR) and temperature programmed oxidation (TPO).Characterization results revealed that functionalization of alumina resulted in improved physicochemical properties of Ni-nanoparticles catalyst compared to the conventional nickel based catalysts. More importantly, a clear improvement on the catalytic hydrogen production and resistance to coke was observed. At all temperature studied Ni.NPs catalyst exhibited high methane conversions which reached to 100% at 750 °C. Also, the Ni.NPs catalysts exhibited high H2 selectivity and excellent thermal stability.The functionalization of alumina with silica improved the dispersion of Ni nanoparticles and prevented sintering and aggregation. Ni.NPs catalyst exhibited stable catalytic activities for a period of 48 h where no carbon deposition was evidenced neither by TPO nor XPS techniques. Contrary to Ni.NPs the conventional nickel catalyst suffered from severe deactivation due to deposition of filamentous carbon on the surface.