Partial oxidation of methane over Ni/Ce-Ti-O catalysts

Partial oxidation of methane (POM) was studied in this work. The supported nickel catalysts were prepared by the coprecipitation-impregnation method. The influence of the molar ratio of Ce/Ti, the calcination temperature, and the content of active component were investigated during the process of preparation. The results show that the mixed oxides of the Ce-Ti-O-supported Ni catalysts exhibited high catalytic activity and stability. Among the catalysts investigated, the highest catalytic activity was observed over 10 wt.% NiO/Ce0.50Ti0.50O2-700 degrees C which showed excellently stable performance during 100 h on stream at 750 degrees C. The catalysts were characterized by DTA/TG, BET, XRD, and TPR. XRD and TPR results confirmed that the NiO in all catalysts was highly dispersed. There was no NiO but only NiTiO3 in the NiO/TiO2 catalyst, due to the reaction between NiO and TiO2. NiTiO3 is harder to be reduced to Ni-0 than NiO. The addition of CeO2 could form a solid solution of Ce-Ti-O, which was able to restrain the reaction between NiO and TiO2 and improve the storage capacity and mobility of oxygen. It was shown that Ni-0 reduced from NiTiO3 was active for the POM reaction. (c) 2006 Elsevier B.V. All rights reserved.