Catalytic Performance For Partial Oxidation Of Methane On Perovskite Oxide LaNiO₃ And Perovskite-like La₂NiO₄

The catalytic partial oxidation of methane(POM) to syngas(CO+H₂) has been extensively investigated since the selectivity of syngas and methane conversion are high and the syngas produced with a molar ratio of H₂/CO as 2:1 can be directly used as feed for methanol or Fischer-Tropsch synthesis. The key problem limiting the further industrial production of syngas by POM process is the catalytic deactivation due to carbon deposition. In this paper, the catalytic performances of POM on perovskite oxide LaNiO₃ and Perovskite-like La₂NiO₄, which prepared by a citric acid method, were studied, and the catalysts were characterized by BET,XRD,TPR,TG/DTA,SEM,XPS.Perovskite oxide LaNiO₃ had been prepared by a citric acid method. The influences of calcination temperature and citric acid amount used in preparing the catalysts were investigated. The results showed that the catalysts prepared with La:Ni:CA=1:1:3 and calcined at 850℃have the best catalytic performance.Perovskite-like La₂NiO₄ were successfully prepared by a citric acid method and used in partial oxidation of methane. Also the influences of calcinations temperature and citric acid amount used in preparing the catalysts were investigated. It was Ni-based catalysts from Perovskite-like La₂NiO₄ precursors were the most active and stable catalyst after calcinations at 850℃, while the proportion of La:Ni:CA=2:1:3. The dosage of the citric acid is also a key factor, by comparing the catalyst with La:Ni:CA=2:1:3 has the best physical performances and showed the higher activity and stability.By comparing the catalytic performances of Perovskite oxide LaNiO₃ and Perovskite-like La₂NiO₄, the later, which has the special superstructure and has a smaller Ni0 after reduction, showed better catalytic performances, After reaction well-defined structure La₂O₂CO₃ phase has been detected on both catalysts, it might be responsible for the unsual catalytic behavior observed over the catalyst.