Enabling complete conversion of CH₄ and CO₂ in dynamic coke-mediated dry reforming (DC-DRM) on Ni catalysts

Abstract

Dynamic coke-mediated dry reforming of methane (DC-DRM) is an unsteady-state strategy to overcome the limitations of co-feed operation, including the fast deactivation of the catalysts and the loss of valuable H₂ in the reverse water gas-shift reaction. This paper proves the feasibility of DC-DRM on Ni-based catalytic systems, identifying suitable metal oxides supports and evaluating the role of metallic promoters. A La-promoted Ni/ZrO₂ catalyst exhibited excellent and stable catalytic performances at 800 °C approaching complete conversion of the CH₄ and CO₂ reactant pulses in the reaction loop, and separation of the H₂ and CO product streams. Adding the redox functionality of reducible oxides (TiO₂) in the catalyst support is demonstrated as a powerful tool to enable direct formation of syngas in the methane pulse with control on the H₂/CO ratio.