CO_2 Reforming of CH_4 over Nickel and Cobalt Catalysts Prepared from La-Based Perovskite Precursors

摘要

Four perovskite-type complex oxides (LaNiO_3, La_2NiO_4, LaCoO_3 and La_2CoO_4) were successfully prepared using two sol-gel methods, the Pechini method (PC) and the citric acid complexing method (CC). The catalysts were characterized by XRD and TPR. After reduction, the activity of the catalysts in the CO_2 reforming of methane was tested. Ni-based catalysts from La_2NiO_4 precursors were the most active and stable catalyst after calcination above 850 ℃, which gave a methane conversion of 0.025 mmol/(g·s) for those prepared by the PC method and 0.020 mmol/(g·s) by the CC method. It was proposed that the well-defined structure and lower reducibility is responsible for the unusual catalytic behavior observed over the pre-reduced La2NiO_4 catalyst.