Combined reforming of methane over co-precipitated Ni–CeO 2, Ni–ZrO 2 and Ni–Ce 0.8Zr 0.2O 2 catalysts to produce synthesis gas for gas to liquid (GTL) process

Abstract

Ni–CeO 2, Ni–ZrO 2 and Ni–Ce 0.8Zr 0.2O 2 catalysts have been prepared by a co-precipitation method to develop catalysts suitable for synthesis gas production for gas to liquid (GTL) process. A conventional impregnation method was also employed to prepare Ni/CeO 2, Ni/ZrO 2 and Ni/Ce 0.8Zr 0.2O 2 catalysts to compare the impregnated catalysts with the co-precipitated ones. Ni content was fixed at 15% for both cases. It has been confirmed that the co-precipitated Ni–CeO 2 and Ni–Ce 0.8Zr 0.2O 2 catalysts exhibited relatively high activity as well as stability, while the impregnated Ni/CeO 2 and Ni/Ce 0.8Zr 0.2O 2 catalysts slowly deactivated with time on stream at 800 °C. At the temperature range from 700 to 750 °C, co-precipitated Ni–Ce 0.8Zr 0.2O 2 catalyst showed higher CH 4 and CO 2 conversion than Ni–CeO 2 catalyst. The enhanced catalytic activity and stability of the co-precipitated Ni–Ce 0.8Zr 0.2O 2 catalyst is due to the combination of nano-crystalline nature of cubic Ce 0.8Zr 0.2O 2 support and finely dispersed nano-sized NiO crystallites resulting in intimate contact between Ni and support, better Ni dispersion, and enhanced oxygen transfer during the reaction.