Methanation of Carbon Dioxide Over Mesoporous Nickel-M-Alumina (M = Fe, Zr, Ni, Y, and Mg) Xerogel Catalysts: Effect of Second Metal

Mesoporous nickel (35 wt%)-M (5 wt%)-alumina xerogel (denoted as 35Ni5MAX) catalysts with different second metal (M = Fe, Zr, Ni, Y, and Mg) were prepared by a single-step sol-gel method for use in the methane production from carbon dioxide and hydrogen. In the carbon dioxide methanation reaction, yield for CH4 decreased in the order of 35Ni5FeAX > 35Ni5ZrAX > 35Ni5NiAX > 35Ni5YAX > 35Ni5MgAX. This indicated that the catalytic performance was greatly influenced by the identity of second metal in the carbon dioxide methanation reaction. Experimental results revealed that CO dissociation energy and metal-support interaction of the catalyst played key roles in determining the catalytic performance of 35Ni5MAX catalysts in the reaction. Among the catalysts tested, 35Ni5FeAX catalyst, which retained the most optimal CO dissociation energy and the weakest metal-support interaction, exhibited the best catalytic performance in terms of conversion of CO2 and yield for CH4. In the carbon dioxide methanation over mesoporous nickel-M-alumina xerogel catalysts with different second metal (M = Fe, Zr, Ni, Y, and Mg), yield for CH4 increased with decreasing TPSR peak temperature and with decreasing metal-support interaction of the catalyst.