Construction of La/NiAl-LDO Catalyst for CO2 Methanation Performance and Reaction Kinetics

CO2 methanation offers a promising technology to convert CO2 into methane, a valuable fuel that can be integrated into existing gas infrastructure. However, developing cost-effective, highly active, and stable catalysts remains a key challenge. In this paper, a series of La/NiAl-LDO catalysts were synthesized via a coprecipitation–impregnation method for catalytic CO2 hydrogenation. Among the prepared catalysts, 6La/NiAl-LDO exhibited the highest CO2 conversion (85.6%) with nearly 100% CH4 selectivity at 300 °C and 2 MPa. The catalyst also demonstrated excellent stability over a 100 h durability test. Moreover, the kinetics of CO2 hydrogenation over a 6La/NiAl-LDO catalyst were studied in a fixed-bed reactor at a catalyst particle size of 20–40 mesh, space velocity of 8000 mL/(g·h)), and temperatures ranging from 260 to 300 °C. The overall positive reaction followed approximately first-order kinetics, with an apparent activation energy of 89.4 kJ/mol. This work contributes to broader efforts in CO2 capture and conversion to synthetic natural gas.