Preparation of Porous NiCe Composite Catalyst and Its Performance for CO₂ Hydrogenation

Abstract Ni component can be effectively introduced into CeO₂ by a soft template method to prepare porous NiCe composite catalysts. The reducibility of the catalyst precursors was studied by H₂‐TPR. The physicochemical properties of the prepared NiCe composite catalysts were characterized by XRD, quasi in‐situ XPS, BET and TEM. And the catalytic performances of the corresponding NiCe composite catalysts was evaluated by CO₂ catalytic hydrogenation. The synergistic effect of Ni and Ce species can significantly improve the reducibility of the precursors to form CO₂ hydrogenation active sites in the corresponding NiCe composite catalysts. The morphology, pore structure, specific surface area, crystallinity and content of metal Ni species of the prepared NiCe composite catalysts were significantly affected by n_Ni/n_Ce ratio, which can affect the CO₂ catalytic hydrogenation performances of NiCe composite catalysts. The synergistic effect of Ni and Ce species can also promote the formation of NiCe composite catalyst nanoparticles with small particle size about 5–10 nm. The developed mesoporous structure and high specific surface area can be formed in the prepared NiCe composite catalysts. The NC3 catalyst with a n_Ni/n_Ce ratio of 3.0 showed the best CO₂ hydroreduction performances and use stability. When the reaction temperature was 300 °C, the CO₂ conversion and CH₄ selectivity can reach 85.6% and 100%, respectively. Even if the reaction temperature rises to 340 °C, the CO₂ conversion and CH₄ selectivity can be maintained at 83.7% and 100% in the continuous reaction of 600 min, respectively.