Suppression of Carbon Deposition during the CO_2-Reforming of CH_4 by the Enhancement of CO_2 Adsorption

摘要

CO_2-reforming of CH_4 was studied from the veiwpoint of the suppression of carbon deposition. Ni/A_2lO_3 catalyst was modified by adding basic metal oxides or replaced with the disulfides of MO and W for such purpose. The oxides of Na, Km Mg, and Ca markedly decreased the activity of a supported Ni for CH_4 decomposition and also suppressed carbon deposition during OC_2-CH_4 reaction. These metal oxides altered the reaction kinetics in a way of the rraction order iwth respect to the CH_4 partial pressure from negative to positive and that with respect to the CO_2 partial pressure from positive to negative. Simialr rsults were also obtained on MoS_2 adn WS_2 catalysts. Their activity for CH_4 decomposition was much smaller than that of supported Ni and carbon deposition was markedly suppressed during CO_2-reforming on the disulfiee catalysts. Reaction kinetics was the same as that on the modified Ni/Al_2O_3 catalyst: positive order with respect to the CH_4 partial pressure and negative order with respect to the CO_2 partial pressure.