수증기 개질반응용 니켈촉매에 첨가된 리튬의 효과 = The effect of added Lithium on nickel catalysts for steam reforming

다국어 초록 (Multilingual Abstract)

In the direct internal reforming type molten carbonate fuel cell, alkali carbonates used as electrolyte in the cell are transported to reforming catalyst of which activity drastically decreases. In our previous work, the deactivation of the nickel catalyst was studied with increasing the amount of added lithium. Unexpectedly, the increase of activity was observed with a small amount of lithium less than 1wt％. The results of TPR, XRD and chemisorption showed no significant difference between the fresh catalyst and the Li-added one, implying that lithium did not cause the change of morphological property of the supported nickel. To elucidate the effect of lithium the methanation of CO was applied to the catalysts, which was considered as the reverse reaction of the key elementary step of methane steam reforming. It can be seen by an online mass spectrometer that the small injection of CO/H₂ mixture into the Li-added catalyst reactor at 650 ℃ showed the longer tail of produced methane than into the fresh one. The delay should be originated from the effect of lithium, which determined the overall rate on the Li-added catalyst.