CeO₂-promoted Ni/Al₂O₃ catalysts were fabricated by impregnation. The effects of the CeO₂ promotion and impregnation order on the microstructural evolution and catalytic durability were investigated for methane steam reforming. The CeO₂-promoter nanoparticles resulted in good dispersion and reduced particle size of Ni catalysts. The enhanced durability of CeO₂-promoted Ni/Al₂O₃ catalysts might be associated with the depression of carbon deposition by the presence of CeO₂-promoter nanoparticles.