Influence of Mg‐promoted Ni‐based Catalyst Supported on Coconut Shell Carbon for CO 2 Methanation

This study aims to investigate the conversion of CO 2 and H 2 into CH 4 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 CO 2 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 CO 2 ‐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 /CO 2 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 CO 2 conversion (90.10%) and CH 4 selectivity (99.22%) at 450 °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.