Thesis (M.Sc.)--Chulalongkorn University, 2006

In this research, the water-in-oil microemulsion was employed to prepare Ce[subscript 1-x]Zr[subscript x]O[subscript 2] mixed oxide which was used as a support. The impregnation method was used to impregnate 15% Ni onto the support. The ratio of CeO[subscript 2] to ZrO[subscript 2] was systematically varied. The prepared catalysts were characterized by various physico-chemical characterization techniques such as X-ray diffraction, X-ray fluorescence, BET surface method, Scanning Electron Microscopy, Energy Dispersive X-ray analysis, and Thermogravimetric analysis. The results showed that cubic Ce[subscript 0.75]Zr[subscript 0.25]O[subscript 2] containing 15% Ni gave synthesis gas from 6.1% methane conversion at 450 degrees Celsius. In contrast, tetragonal Ce-ZrO[subscript 2] (Ce[subscript 0.5]Zr[subscript 0.5]O[subscript 2] and Ce[subscript 0.15]Zr[subscript 0.85]O[subscript 2] containing 15% Ni gave lower methane conversion and was deactivated during the reaction due to the carbon formation. By varying the amount of Ni loading from 5 to 20%, it was found that Ce[subscript 0.75]Zr[subscript 0.25]O[subscript 2] with 15% nickel loading exhibited the highest catalytic activity. Then various amounts of Ru were impregnated onto 15% Ni/Ce[subscript 0.75]Zr[subscript 0.25]O[subscript 2]. Their catalytic activities in dry reforming of methane were determined. The results indicated that 0.7% Ru on Ni catalyst had the highest reforming activity which was 6.9% of methane conversion. It can be concluded that 15%Ni-0.7%Ru/Ce[subscript 0.75]Zr[subscript 0.25]O[subscript 2] catalyst exhibited the best activity in best activity in dry reforming of methane at 450 degrees Celsius for 17 h.