Partial oxidation of methane to synthesis gas over Pt nanoparticles supported on nanocrystalline CeO2 catalyst

Abstract

Pt-nanoparticles supported on CeO₂ have been prepared by a post synthesis method (Pt–CeO₂^PS). In the post synthesis method, CeO₂ nanoparticles were prepared by a hydrothermal method, followed by the deposition of Pt nanoparticles over the CeO₂. The prepared catalyst was characterized by XRD, BET-surface area, TPR, SEM, TEM, XPS and XAFS. It was observed that the catalyst prepared by the post synthesis method contained Pt nanoparticles with sizes between 2–5 nm supported on CeO₂ nanoparticles with sizes between 20–60 nm. The catalytic performance of the Pt–CeO₂^PS catalyst was evaluated in the partial oxidation of methane for synthesis gas production. The Pt–CeO₂^PS catalyst could activate methane at 350 °C. We believe that the nanosized Pt particles and the synergy between the Pt particles, the CeO₂ nanoparticles and the presence of a strong metal–support interaction play key roles in the activation of methane at such a low temperature. Different reaction parameters, like Pt-loading, reaction temperature, space velocity, and time on stream, were studied in detail. The Pt–CeO₂^PS catalyst does not deactivate till 100 h with a constant H₂/CO mole ratio of 1.9 at 800 °C.