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 °C which showed excellently stable performance during 100 h on stream at 750 °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 Ni0 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 Ni0 reduced from NiTiO3 was active for the POM reaction.