La1-x Cax MnO3 (x=0-0.3) perovskite-type oxides were synthesized by citrate sol-gel method. The physical and chemical properties were characterized by X-ray diffraction (XRD), Brumauer-Emmett-Teller method (BET)...La1-x Cax MnO3 (x=0-0.3) perovskite-type oxides were synthesized by citrate sol-gel method. The physical and chemical properties were characterized by X-ray diffraction (XRD), Brumauer-Emmett-Teller method (BET), X-ray photoelectron spectroscopy (XPS), NO+O2 -TPD (temperature-programmed desorption), activated oxygen evaluation and H2 -TPR (temperature-programmed reduction) technologies. The results showed that NO catalytic oxidation activity was significantly improved by Ca substitution, especially for lower temperature activity. The La0.9 Ca0.1 MnO 3 sample showed the maximum conversion of 82% at 300 oC. The monodentate nitrates played a crucial role for the formation of NO2 . The reducibility of Mn 4+ ions and reactivity of activated oxygen were favorable for the catalytic performances of NO oxidation.展开更多
基金Project supported by National High Technology Research and Development Program of China(863Program,2011AA03A405)
文摘La1-x Cax MnO3 (x=0-0.3) perovskite-type oxides were synthesized by citrate sol-gel method. The physical and chemical properties were characterized by X-ray diffraction (XRD), Brumauer-Emmett-Teller method (BET), X-ray photoelectron spectroscopy (XPS), NO+O2 -TPD (temperature-programmed desorption), activated oxygen evaluation and H2 -TPR (temperature-programmed reduction) technologies. The results showed that NO catalytic oxidation activity was significantly improved by Ca substitution, especially for lower temperature activity. The La0.9 Ca0.1 MnO 3 sample showed the maximum conversion of 82% at 300 oC. The monodentate nitrates played a crucial role for the formation of NO2 . The reducibility of Mn 4+ ions and reactivity of activated oxygen were favorable for the catalytic performances of NO oxidation.