Cobalt Molybdenum Carbides: Preparation and Reactivity for Methane Decomposition

Abstract

The decomposition of methane for hydrogen production over a Co–Mo catalyst with 25% Co loading carbided at various temperatures was studied at 973 K and atmospheric pressure. The 700 K-carbided catalyst was the most active of the other catalysts for H₂ production (above 98%) in the decomposition at 44 h. The Co–Mo catalysts carbided at 725 and 750 K were also active at 44 h, while the catalyst carbided at 800 K was active for 1 h but quickly deactivated. The catalysts carbided at 873 and 973 K were less active. The XRD analysis showed that the catalysts carbided at 700–750 K consisted of MoO₂ and CoMoO₄ which were turned to CoMoO_xC_y, β-Mo₂C, and Co metal during the CH₄ decomposition. The carbiding at 800 K produced CoMoO_xC_y which changed to β-Mo₂C and Co metal after the reaction. The carbiding at 873 and 973 K contained β-Mo₂C and Co metal. The effects of two carbiding methods of different heating rates, H₂ pretreatment, and CO₂ addition on the catalytic activity and hydrogen production were studied.