Ceria-Doped Ni/SBA-16 Catalysts for Dry Reforming of Methane

Abstract

Ni-ceria nanoparticles (Ni/Ce = 1/1) in the cage-like pores of SBA-16 were prepared and evaluated in methane dry reforming reactions. Coexistence of ceria in NiCe/SBA-16 resulted in forming uniformly sized Ni particles (av. 5.7 nm) within the mesopores of SBA-16, because of the confinement effect from the framework of SBA-16 and the strong interaction between Ni and ceria. Ceria addition facilitated the reduction of NiCe/SBA-16 compared with Ni/SBA-16, and Ce³⁺ was the dominant species in both fresh and used NiCe/SBA-16 catalysts, as determined by Ce L_III-edge X-ray absorption near-edge structure (XANES). The methane conversion was much more stable on NiCe/SBA-16 than on Ni/CeO₂ and Ni/SBA-16 in the methane dry reforming at 973 K during a 100 h reaction period; the deactivation of the Ni catalyst and the collapse of the SBA-16 framework were preferably suppressed for NiCe/SBA-16 under the reaction conditions. The remarkable effect of ceria on the structural stability of both the active Ni particles and the SBA-16 framework led to the consistent catalytic performance of NiCe/SBA-16 in methane dry reforming