Bimetallic molybdenum nitride Co3Mo3N: a new promising catalyst for CO2 reforming of methane

Abstract

CO₂ (dry) reforming of methane (DRM) has received much attention as an important process for the transformation and applications of two greenhouse gases (CH₄ and CO₂). In the present study, non-precious monometallic molybdenum nitride Mo₂N and bimetallic molybdenum nitrides Ni₃Mo₃N and Co₃Mo₃N were synthesized and used as catalysts for DRM. It was found that the Mo₂N, Ni₃Mo₃N and Co₃Mo₃N materials were catalytically active in the DRM reaction above 550 °C. Compared to the monometallic nitride Mo₂N, the bimetallic nitrides Co₃Mo₃N and Ni₃Mo₃N showed enhanced catalytic activity, stability and resistance to oxidation. Particularly, Co₃Mo₃N exhibited the highest activity and stability among the three samples, which could be due to three factors, namely, the synergistic effect between the Mo and interstitial metal Co in the interstitial structure, the roughly equal adsorption capacities and consumption rates of reactants CO₂ and CH₄ and their increment on the surface of the catalyst at high reaction temperatures, as well as a possible conversion balance on the active centers established. The results suggest that the low-cost Co₃Mo₃N is a promising candidate for DRM.