Effect of lithium carbonate on nickel catalysts for direct internal reforming MCFC

Several supported nickel catalysts deactivated by lithium carbonate were prepared, characterized and evaluated. The Ni/MgO catalyst turned out to be most vulnerable to lithium deactivation among the employed catalysts. The activity of the Ni/MgO gradually decreased to zero with increasing amount of lithium addition. Deactivation by lithium addition resulted from the decrease of active site due to sintering of nickel particles as well as the formation of the LiyNixMg1−x−yO ternary solid solution. These were evidenced by H2 chemisorption, temperature programmed reduction, and XRD analyses. As an effort to minimize Li-poisoning, titanium was introduced to MgO support. This resulted in the formation of Ni/Mg2TiO4, which seemed to increase resistance against Li-poisoning.