Synthesis and Evaluation of Nickel-Based Catalysts for Methane Tri-Reforming

The catalytic tri-reforming process involves synergetic combination of dry reforming, steam reforming and partial oxidation of methane. In such a combined process, CO₂ emissions from a power plant flue gas can be utilized to produce syngas with a suitable H₂:CO ratio desired for the Fischer-Tropsch process and methanol synthesis without the need for the CO₂ pre-separation step.

The tri-reforming process requires a novel catalyst that is thermally stable at temperatures between 700 °C and 900 °C and has a high surface area, good redox properties, and high O₂ storage capacity. Typically nickel-based catalysts are reported to have high activity for both steam and dry reforming processes. However, nickel particles supported on metal oxides tend to deactivate through coke formation and sintering. The deactivation of the catalyst is influenced by the catalyst structure, metal dispersion, and composition.

In this work, a series of nickel-based catalysts supported on Al₂O₃, SiO₂, CeO₂ and YSZ have been evaluated for their performance in the tri-reforming reaction under simulated natural gas combustion flue gas. Throughout these catalysts Ni/Al₂O₃ showed the highest CH₄ conversion of 72% with a CO₂ conversion of 57% at 850 °C. In addition, Ni/CeO2 indicated lower CH₄ and CO₂ conversions of 61% and 40%, respectively. Both Ni/Al2O3 and Ni/CeO2 catalysts showed a H₂:CO ratio of 1.75.

Additional efforts focus on synthesizing Nickel/Ceria nanorods and Nickel@Ceria core-shell nanoparticles, which could be an effective catalyst for the tri-reforming reaction. Details of the synthesis methodologies and characterization of the catalysts will be discussed.