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

Abstract

Ni component can be effectively introduced into CeO 2 by a soft template method to prepare porous NiCe composite catalysts. The reducibility of the catalyst precursors was studied by H 2 -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 CO 2 catalytic hydrogenation. The synergistic effect of Ni and Ce species can significantly improve the reducibility of the precursors to form CO 2 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 CO 2 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 CO 2 hydroreduction performances and use stability. When the reaction temperature was 300 °C, the CO 2 conversion and CH 4 selectivity can reach 85.6% and 100%, respectively. Even if the reaction temperature rises to 340 °C, the CO 2 conversion and CH 4 selectivity can be maintained at 83.7% and 100% in the continuous reaction of 600 min, respectively.

Progress in reaction mechanisms and catalyst development of ceria-based catalysts for low-temperature CO2methanation

“…Consequently, the CO 2 conversion of ∼70% can be maintained at 300 °C under a high GHSV of 120 000 mL g −1 h −1 for 50 h over Ni–CeO 2 -CSC. To further optimize the pore structure of the Ni/CeO 2 catalyst, Zhou et al 137 prepared a series of NiCe composite samples with different n Ni / n Ce ratios by a soft template method. The physicochemical properties of as-prepared NiCe catalysts were highly correlated with the n Ni / n Ce ratio.…”