Influence of Mg-promoted Ni-based Catalyst Supported on Coconut Shell Carbon for CO2 Methanation

This study aims to investigate the conversion of CO2 and H-2 into CH4 under atmospheric pressure. A series of nickel-based catalysts using coconut shell carbon were prepared by co-impregnation method, and the coconut shell carbon carrier in the CO2 methanation demonstrated its advantage by comparison with the alumina and zirconia supports. Magnesium modified Ni/coconut shell carbon catalysts were studied to explore the catalytic performances, the morphology and properties of all catalysts were characterized by CO2-TPD, XRD, SEM, BET, FTIR, TEM and H-2-TPR. Catalytic performances were experimentally evaluated in a fixed bed tubular reactor under atmospheric pressure, WHSV of 10,000 mlh(-1)g(-1), and H-2/CO2 molar ratio of 4/1. Experimental results indicated magnesium modified Ni-Mg-0.26/coconut shell carbon catalyst has outstanding activity and excellent stability, which performed the highest CO2 conversion (90.10%) and CH4 selectivity (99.22%) at 450 degrees C. The catalytic activity of Ni-Mg-0.26/ coconut shell carbon experienced 50 h stability evaluation, and no evident decrease was found during the methanation process.