(582e) Carbon Dioxide Reforming of Methane to Synthesis Gas Over Nickel Incorporated Ni-Mcm-41 Catalysts

A series of nickel incorporated MCM-41 mesoporous molecular sieves was synthesized using nickel nitrate as the Ni source. The catalytic properties of Ni-MCM-41 were studied for the reforming of methane with carbon dioxide. The catalysts were extensively characterized by X-ray diffraction, N2 adsorption, H2 temperature-programmed reduction, thermogravimetry, and Raman spectra. The results indicate that the presence of the suitable amount of Ni in Ni-MCM-41 is beneficial for maintaining high catalytic activity and long term stability. The improved catalytic performance is associated closely with both the amount of active centers and stabilized dispersion of these sites by silica matrix or surrounding Ni2+ ions. This anchoring effect facilitates the formation of the active Ni clusters with high dispersion under reaction conditions, thus favoring the reforming reaction but suppressing the carbon formation. Two types of carbon species, active carbon and graphitic carbon, are produced over the spent catalysts, with the amount of the former being higher than that of the latter, irrespective of the pretreatment method. With the Ni-MCMC-41 catalysts, the better catalytic activity, long time stability and the higher CO/H2 ratio in product can be resulted in. Thus, The Ni-MCM-41 catalyst with stable dispersed Ni clusters promises a novel and stable catalyst candidate for CO2 reforming of CH4.