CoCe composite catalyst for CO2 hydrogenation: Effect of pore structure

In order to realize the dual carbon goals of “carbon peaking” and “carbon neutrality”, the design and development CO₂ hydrogenation catalyst with high performances is of great significance. In this study, the CoCe composite catalysts were prepared by different methods and used to CO₂ catalytic hydrogenation. The physicochemical properties of the prepared catalysts were characterized by XRD, BET, TEM/HRTEM, and H₂-TPD. The characterization results indicated that the studied CoCe composite catalytsts with different pore structure can be prepared by different preparation methods. The suitable preparation method can promote Co species to be dissolved into the CeO₂ lattice to form Ce-O-Co solid solution, which can promote the corresponding Co species to be reduced by H₂ to form active Co⁰ species. The large specific surface area and developed ordered mesoporous structure of the CoCe-HT catalyst precursor, which was prepared by hard-template method, are conducive to the formation of active Co⁰ species and activation of H₂ to produce reactive H species. The CO₂ hydrogenation activity of the studied CoCe composite catalysts follows the following order: CoCe-HT > CoCe-CP > CoCe-CA > CoCe-HY. The CoCe-HT catalyst showed high CO₂ hydrogenation conversion of 53.9 % and good using stability at 360 °C for 600 min. However, the CoCe-CA prepared by complex method has a poor use stability.