(710e) Methane Dry Reforming at Low Temperatures over Pt-Ni-Mg/Ceria-Zirconia Catalysts

Low temperature dry reforming of methane was studied over platinum (0.2-2 wt. %) and/or nickel (8 wt. %) and magnesium (8 wt. %) immobilized onto a ceria-zirconia support. XRD patterns demonstrated that the support (Ce_0.6Zr_0.4) was a cubic fluorite structure and Ni and Mg were immobilized onto it. Temperature-programmed reduction showed that Pt addition significantly decreased the reduction temperature and the impact became less prominent with increasing Pt loading. The Ni-Mg/(Ce_0.6Zr_0.4)O₂ had the highest number of basic sites and the amount decreased with the addition of platinum. The lowest CH₄ and CO₂ conversion (X₁₀) temperatures were achieved at 454°C and 437°C respectively using a 0.5%Pt-Ni-Mg/(Ce_0.6Zr_0.4)O₂ catalyst. Dry reforming experiments also indicated that Pt decreased the reaction onset temperature for methane and CO₂ and correlated to a slight decrease in the H₂:CO ratio (though still higher than for the 0.5%Pt- Ce_0.6Zr_0.4O₂ control catalyst). Steady-state reaction experiments were conducted between 430 and 470°C for the best catalyst and the results showed TOFs increasing from 2.69 to 4.74s^-1 with increasing temperature and minimal deactivation when left on stream for 100.5 hours.