Ir-Promoted Cobalt-Based Catalysts for Dry Reforming of Methane

Dry reforming of methane (DRM) affording key raw materials (H₂and CO) for the production of fuels and chemicals is rising to be an economically advantageous technology for removing two major greenhouse gases (CO₂and CH₄). However, cheap and high-performing catalysts are still under investigation. Herein, we explored the incorporation of iridium into cobalt-based catalysts for promoted DRM based on our optimized MgAl₂O₄support. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) analysis, X-ray photoelectron spectroscopy (XPS), H₂temperature-programmed reduction (H₂-TPR), and thermogravimetric (TG) characterization experiments reveal that the addition of iridium can enhance the dispersion of Co sites and the formation of Co²⁺active species under lowered reduction temperatures, likely due to the subtle interplay between the enriched electronic state of the support and the hydrogen spillover effect. Importantly, compared to the parent catalyst 8Co/MgAl₂O₄, the optimal catalyst 8Co-0.5Ir/MgAl₂O₄with the addition of 0.5 wt % iridium exhibits 75% improved coke resistance (3.68 vs 15.02% carbon deposition) and 12% improved catalytic activity (78 vs 66% for CH₄conversion) at 700 °C over a 30 h operation.