Synergistic Effect of CeO2 in CH4/CO2 Dry Reforming Reaction over Stable xCeO2 yNi/MCM-22 Catalysts

Ceria-supported Ni/MCM-22 catalysts with weight ratio of Ni:CeO2 (9:0, 9:4, 9:8, 9:12) were prepared by a sol gel method. The effect of CeO2 on activity and stability of catalysts was evaluated at 700-750 degrees C with gas hour space velocity of 2.4X 10(4) mL Cl h(-1). The presence of CeO2 in Ni/MCM-22 suppressed effectively the accumulation of coke on active Ni sites via the oxygen storage capacity on the interface between elemental nickel and CeO-Si groups of MCM-22. H-2 temperature -programmed reduction results illustrated that CeO2 reduced the interaction between Ni and MCM22 and increased the high dispersion of Ni nanoparticles, which is easily reducible. The 8CeO(2) 9Ni/MCM-22 catalyst performed the best at 750 degrees C with the lowest carbon deposition during time on stream of 60 h, plausibly due to the presence CeO2, which promotes C-H activation. Moreover, the surface oxygen species on the catalyst can interact with the coke generated during reaction to suppress the formation of coke.