Nitrided Ni/N-zeolites as efficient catalysts for the dry reforming of methane

Abstract

N-ZSM-5 and N-beta zeolites with enhanced basic properties were prepared by substituting the framework oxygen with nitrogen using the high temperature nitridation with ammonia. The basic zeolites and their acidic counterparts were impregnated with Ni by the incipient wetness impregnation method and their catalytic properties for the dry reforming of methane (DRM) were investigated. The physicochemical properties of the prepared catalysts, such as the chemical state of nickel and properties of the framework nitrogen and acid-bases, were characterized by elemental analysis, 29Si MAS NMR, NH3 and CO2 TPD, IR, XPS, and H2 chemisorption. For all the catalysts, the DRM activity according to time on stream was compared by changing the temperature under the identical conditions. From the overall results, we demonstrated that the nitrided Ni/N-ZSM-5 exhibited superior DRM activity to the Ni/H-ZSM-5 especially at high temperature owing to the enhanced basic property and dispersion of Ni active species.