Effect of calcination temperature and reaction conditions on methane partial oxidation using lanthanum-based perovskite as oxygen donor  

作　　者：代小平 余长春 李然家 吴琼 史凯娇 郝郑平 

机构地区：[1]The Key Laboratory of Catalysis CNPC, University of Petroleum [2]Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China [3]Research Center for Eco-Environmental Science, Chinese Academy of Sciences

出　　处：《Journal of Rare Earths》2008年第3期341-346,共6页稀土学报（英文版）

基　　金：the National Natural Science Foundation of China (20306016, 20322201)

摘　　要：We investigated the effect of calcination temperature, reaction temperature, and different amounts of replenished lattice oxygen on the partial oxidation of methane （POM） to synthesis gas using perovskite-type LaFeO3 oxide as oxygen donor instead of gaseous oxygen, which was prepared by the sol-gel method, and the oxides were characterized by XRD, TG/DTA, and BET. The results indicated that the particle size increased with the calcination temperature increasing, while BET and CH4 conversion declined with the calcination temperature increasing using LaFeO3 oxide as oxygen donor in the absence of gaseous oxygen. CO selectivity remained at a high level such as above 92%, and increased slightly as the calcination temperature increased. Exposure of LaFeO3 oxides to methane atmosphere enhanced the oxygen migration of in the bulk with time online owing to the loss of lattice oxygen and reduction of the oxidative stated Fe ion simultaneously, The high reaction temperature was favorable to the migration of oxygen species from the bulk toward the surface for the synthesis gas production with high CO selectivity. The product distribution and evolution for POM by sequential redox reaction was determined by amounts of replenished lattice oxygen with gaseous oxygen. The optimal process should decline the total oxidation of methane, and increase the selectivity of partial oxidation of methane.We investigated the effect of calcination temperature, reaction temperature, and different amounts of replenished lattice oxygen on the partial oxidation of methane （POM） to synthesis gas using perovskite-type LaFeO3 oxide as oxygen donor instead of gaseous oxygen, which was prepared by the sol-gel method, and the oxides were characterized by XRD, TG/DTA, and BET. The results indicated that the particle size increased with the calcination temperature increasing, while BET and CH4 conversion declined with the calcination temperature increasing using LaFeO3 oxide as oxygen donor in the absence of gaseous oxygen. CO selectivity remained at a high level such as above 92%, and increased slightly as the calcination temperature increased. Exposure of LaFeO3 oxides to methane atmosphere enhanced the oxygen migration of in the bulk with time online owing to the loss of lattice oxygen and reduction of the oxidative stated Fe ion simultaneously, The high reaction temperature was favorable to the migration of oxygen species from the bulk toward the surface for the synthesis gas production with high CO selectivity. The product distribution and evolution for POM by sequential redox reaction was determined by amounts of replenished lattice oxygen with gaseous oxygen. The optimal process should decline the total oxidation of methane, and increase the selectivity of partial oxidation of methane.

关 键 词：perovskite LaFeO3 lattice oxygen synthesis gas redox reaction rare earths 

分 类 号：O621.2[理学—有机化学]