Abstract
Two kinds of typical perovskite catalysts La_<1-x>Sr_xMnO_3 (x=0.2, 0.4) as new catalysts for using in CH_4-NO and CH_4-N_2O reaction is proposed, and the preparation method, characterization, catalytic activity of La_<1-x>Sr_xMnO_3 was investigated. The catalysts powder via sol-gel method was successfully synthesized in this paper. In addition, the catalytic activity of supported La_<1-x>Sr_xMnO_3 catalyst was tested in fixed bed reactor, and the effects O_2 concentration on catalyst activity were explored at three different temperatures, 600℃, 700℃ and 800℃. The catalytic reduction of NO and N_2O by CH_4 over La_<0.8>Sr_<0.2>MnO_3 and La_<0.6>Sr_<0.4>MnO_3 catalyst was performed separately. The conversion ratio of N_2O was usually higher than that of NO when the temperature and other conditions were the same. With the decrease of temperature, the range of O_2 concentration becomes narrower obviously on the NO conversion. However, the O_2 content doesn't seem to have significant influence on the N_2O conversion ratio. The La_<0.8>Sr_<0.2>MnO_3 performed better on the reaction of CH_4 and N_2O when temperature increased, while the La_<0.6>Sr_<0.4>MnO_3 performed best on 700℃ with a ratio of about 90%.
