Nickel Modified Molybdenum Carbide Catalyst For Carbon Dioxide Reforming Of Methane To Syngas

The synthesis gas with a low hydrocarbon ration produced by the reforming of methane with carbon dioxide provides an ideal raw material for Fischer-Tropsch synthesis. While CO2 being a reactant, this not only reduce greenhouse gas emissions to some extent, but also make CO2 as an available carbon source. So this reforming reaction is significant on resource conservation and the development of low-carbon economy when easing the increasingly serious environmental problems. Although the reforming has many environmental and economic advantages, this still has not been industrialized, which mainly due to the high cost of precious metals and the serious problem of nickel-based catalysts coking. In this paper, metal molybdenum carbide and nickel modified molybdenum carbide catalyst were prepared and their catalytic performances were investigated for CH4-CO2 reforming reaction in laboratory scale. The main content was described from three aspects as follows:1. Mo2C was prepared from the precursor MoO3 by temperature programmed carbonization method and characterized by XRD analysis. Carbonization temperature, Mo2C/Al2O3, and the impact from plasma discharge on activity and stability of CH4-CO2 reforming reaction with Mo2C being the catalyst were also studied. The results show that low-speed and high temperature at atmospheric pressure are conducive to Mo2C stability, and plasma discharge has little effect on its activity. The main reason of catalyst deactivation is Mo2C oxidation inactivation rather than coke.2. NiMoOx and Ni-Mo2C were prepared by co-precipitation and temperature programmed carbonization method respectively. The effect of added nickel on carburized temperature of the carbide was studied. We also investigated the impact of different Ni/Mo ratio, GHSV, synthesis temperature on the catalytic activity and stability of Ni-Mo2C catalyst at atmospheric pressure and high temperature. The results show that under atmospheric pressure Ni-Mo2C catalyst has high stability, and within the experimental 36 hours the activity is relatively stable, the conversion rate of CH4 can reach to 85%.3. The reaction mechanism was studied by temperature programmed reduction (CH4-TPR) and temperature programmed oxidation (CO2-TPO). The results show that the addition of nickel is facilitated for carbide synthesis and promoting methane decomposition, therefore it is conducive to the stability of molybdenum carbide at atmospheric pressure.