La<sup>0.8 Cu<sup>0.2 MnO<sup>3±δ perovskite-type catalyst for methane combustion prepared through sol-gel process was characterized by X-ray Diffractometry（XRD）, X-ray Photoelectron Spectros...La<sup>0.8 Cu<sup>0.2 MnO<sup>3±δ perovskite-type catalyst for methane combustion prepared through sol-gel process was characterized by X-ray Diffractometry（XRD）, X-ray Photoelectron Spectroscopy（XPS） and Scanning Electron Microscopy（SEM）. XPS analyses reveal that the surface characteristics of the catalyst are changed. The lattice defects and oxygen vacancies on the catalyst surface are enhanced due to a part of La3+ being substituted by Cu2+ . Temperature-programmed-desorption（TPD） and temperature-programmed-reduction（TPR） analyses were carried out to study the catalytic behavior. It is found that there are two O2-desorption peaks at 350℃ and 650℃ in the TPD pattern, and two CH4-consumption peaks at 420℃ and 750℃ in the TPR patterns respectively, which indicates that the two kinds of oxygen species, so-called α and β oxygen, can react with the methane during catalytic combustion process. The catalytic activity tests were performed in a fixed-bed reactor, and the results show that the T<sup>1/2 at which the conversion of methane attains 50% of La<sup>0.8 Cu<sup>0.2 MnO<sup>3±δ is lower by 55℃ than that of LaMnO3. This indicates that the catalytic activity of-La<sup>0.8 Cu<sup>0.2 MnO<sup>3±δ is increased with partial substitution of Cu2+ for La3+ .-展开更多
Iron-based perovskite-type compounds modified by Ru were prepared through sol-gel process to study its catalytic activity of NOx direct decomposition at low temperature and evaluate the conversion of NO under the expe...Iron-based perovskite-type compounds modified by Ru were prepared through sol-gel process to study its catalytic activity of NOx direct decomposition at low temperature and evaluate the conversion of NO under the experimental conditions. The catalytic activity of La 0.9Ce 0.1Fe 0.8-nCo 0.2RunO3 （n=0.01,0.03,0.05,0.07,0.09）series for the NO, NO-CO two components, CO-HC-NO three components were also analyzed. The catalytic investigation evidenced that the presence of Ru is necessary for making highly activity in decomposition of nitric oxide even at low temperature（400 ℃）and La 0.9Ce 0.9Fe 0.75Co 0.2Ru 0.05O3 （n=0.05） has better activity in all the samples, the conversion of it is 58.5%. With the reducing gas（CO,C3H6）added into the gas, the catalyst displayed very high activity in decomposition of NO and the conversion of it is 80% and 92.5% separately.展开更多
文摘La<sup>0.8 Cu<sup>0.2 MnO<sup>3±δ perovskite-type catalyst for methane combustion prepared through sol-gel process was characterized by X-ray Diffractometry（XRD）, X-ray Photoelectron Spectroscopy（XPS） and Scanning Electron Microscopy（SEM）. XPS analyses reveal that the surface characteristics of the catalyst are changed. The lattice defects and oxygen vacancies on the catalyst surface are enhanced due to a part of La3+ being substituted by Cu2+ . Temperature-programmed-desorption（TPD） and temperature-programmed-reduction（TPR） analyses were carried out to study the catalytic behavior. It is found that there are two O2-desorption peaks at 350℃ and 650℃ in the TPD pattern, and two CH4-consumption peaks at 420℃ and 750℃ in the TPR patterns respectively, which indicates that the two kinds of oxygen species, so-called α and β oxygen, can react with the methane during catalytic combustion process. The catalytic activity tests were performed in a fixed-bed reactor, and the results show that the T<sup>1/2 at which the conversion of methane attains 50% of La<sup>0.8 Cu<sup>0.2 MnO<sup>3±δ is lower by 55℃ than that of LaMnO3. This indicates that the catalytic activity of-La<sup>0.8 Cu<sup>0.2 MnO<sup>3±δ is increased with partial substitution of Cu2+ for La3+ .-
基金Sponsored by the National Natural Science Foundation of China(Grant No.20271019 and 20576027), Natural Science Foundation of Heilongjiang Prov-ince(Grant No.B200504), Postdoctoral Foundationof Heilongjiang Province(Grant No.LBH-Z05066) and Education Department Foundation of Hei-longjiang Province(Grant No.11511270).
文摘Iron-based perovskite-type compounds modified by Ru were prepared through sol-gel process to study its catalytic activity of NOx direct decomposition at low temperature and evaluate the conversion of NO under the experimental conditions. The catalytic activity of La 0.9Ce 0.1Fe 0.8-nCo 0.2RunO3 （n=0.01,0.03,0.05,0.07,0.09）series for the NO, NO-CO two components, CO-HC-NO three components were also analyzed. The catalytic investigation evidenced that the presence of Ru is necessary for making highly activity in decomposition of nitric oxide even at low temperature（400 ℃）and La 0.9Ce 0.9Fe 0.75Co 0.2Ru 0.05O3 （n=0.05） has better activity in all the samples, the conversion of it is 58.5%. With the reducing gas（CO,C3H6）added into the gas, the catalyst displayed very high activity in decomposition of NO and the conversion of it is 80% and 92.5% separately.
