Catalytic studies of Pt supported on Co/CeO2 nanorods for H2 production in dry reforming of methane

Abstract

An integrated experimental–theoretical study was performed on 15Co/CeO₂ nanorod catalysts with varying Pt loadings (0.1–0.5 wt%) for dry reforming of methane (DRM) to syngas. CeO₂ nanorods were synthesized hydrothermally and sequentially impregnated with Co and Pt. The catalysts were characterized by XRD, TPR, TPO, CO₂- and NH₃-TPD, and TEM/STEM-EDX, while DFT calculations were conducted to evaluate the proposed reaction mechanism and transition states. TEM revealed isolated Pt and Co nanoparticles anchored to CeO₂ surfaces. The monometallic Co/CeO₂-NR catalyst exhibited pronounced deactivation and significant sintering, whereas Pt-promoted catalysts showed enhanced stability despite increased graphitic carbon deposition. Post-reaction SEM and TEM indicated partial detachment of the active phase associated with carbon nanotube growth which contributes to catalyst deactivation. Energy transition state profiles by Halgren–Lipscomb showed no significant decrease in activation energy with increasing Pt content; however, catalytic tests demonstrated higher reactant conversions, suggesting that Pt enhances DRM performance through mechanisms beyond simple energy barrier reduction.