Enhancing CO2 methanation via doping CeO2 to Ni/Al2O3 and stacking catalyst beds

Abstract

This work synthesized a series of Ni/CeO₂/Al₂O₃ catalysts with varying CeO₂ doping amounts to enhance low-temperature CO₂ methanation. The introduction of CeO₂ weakens the interaction between Ni and Al₂O₃, leading to the formation of Ni-CeO₂ active sites. This results in a high dispersion of Ni and CeO₂, improved catalyst reducibility, increased number of active sites, and enhanced the CO₂ methanation. This work further investigated the impact of WHSV and catalyst stacking configuration to enhance the reaction. When the catalyst is stacked into three segments with a temperature gradient of 330 °C, 300 °C, and 250 °C under WHSV = 9000 ml·h^–1·g⁻¹, the CO₂ conversion significantly increases to 95%, which is remarkably close to the thermodynamic equilibrium (96%).