Development of nickel catalyst supported on MgO–TiO 2 composite oxide for DIR-MCFC

Abstract

As an effort to synthesize supported Ni reforming catalysts resistant to Li poisoning, which is essential in commercializing the direct internal reforming molten carbonate fuel cells (DIR-MCFC), a series of Ni catalysts supported on MgO–TiO 2 composite oxides with varying ratio of Mg to Ti were prepared. Under the Li-free condition, the supported Ni reforming catalysts were active regardless of the ratio of Mg to Ti; however, when Li was introduced to the catalysts, the catalysts lost their activities with different degrees. Temperature-programmed reduction (TPR) and X-ray diffraction (XRD) results indicated that the addition of relatively small fraction of TiO 2 into the NiO/MgO catalyst system was effective in obstructing the formation of Ni x Mg 1− x O solid solution and in increasing resistance to Li poisoning. The Ni catalysts supported on the composite oxides with Mg/Ti ratios of 2–7 turned out to be far more resistant to Li poisoning, showing approximately 60% of their original activities even under severe lithium carbonate condition, than the ones with other Mg/Ti ratios.