The double perovskite oxides Sr2Mg1-xF exMoO6-δ were investigated as catalysts for the methane oxidation.The structural properties of catalysts were characterized in detail by X-ray diffraction,X-ray photoelectron sp...The double perovskite oxides Sr2Mg1-xF exMoO6-δ were investigated as catalysts for the methane oxidation.The structural properties of catalysts were characterized in detail by X-ray diffraction,X-ray photoelectron spectroscopy and X-ray absorption spectroscopy.The catalytic property was strongly influenced by the Fe substitution.The relation between catalytic performance and the degree of Fe substitution was examined with regard to the structure and surface characteristics of the mixed oxides.The Fe-containing catalysts exhibited higher activity attributable to the possible（Fe2＋,Mo6＋） and （Fe3＋,Mo5＋）valency pairs,and the highest activity was observed for Sr2Mg0.2Fe0.8MoO6-δ.The enhancement of the catalytic activity may be correlated with the Fe-relating surface lattice oxygen species and was discussed in view of the presence of oxygen vacancies.展开更多
The VUV-UV spectroscopic properties of Ce3＋ in Ba2Mg（BO3）2,Ba2Ca（BO3）2 and Sr2Mg（BO3）2 were compared,and the relation between the energy of the 4f→5d transition of Ce3＋ and the coordination environments of su...The VUV-UV spectroscopic properties of Ce3＋ in Ba2Mg（BO3）2,Ba2Ca（BO3）2 and Sr2Mg（BO3）2 were compared,and the relation between the energy of the 4f→5d transition of Ce3＋ and the coordination environments of substituted alkaline earth ions was discussed.The chromaticity coordinates of Ce3＋ activated X2Z（BO3）2（X=Ba,Sr;Z=Ca,Mg） phosphors were changeable from blue to whitish and further to green range by varying the doping concentration of Ce3＋ or the types of substituted alkaline earth ions upon 172 nm excitation.展开更多
基金the financial supports from the National Natural Science Foundation of China(No.20703042)National Basic Research Program of China(No.2010CB923300)+1 种基金USTC-NSRL Association Funding(No.KY2060030009)the Fundamental Research Funds for the Central Universities
文摘The double perovskite oxides Sr2Mg1-xF exMoO6-δ were investigated as catalysts for the methane oxidation.The structural properties of catalysts were characterized in detail by X-ray diffraction,X-ray photoelectron spectroscopy and X-ray absorption spectroscopy.The catalytic property was strongly influenced by the Fe substitution.The relation between catalytic performance and the degree of Fe substitution was examined with regard to the structure and surface characteristics of the mixed oxides.The Fe-containing catalysts exhibited higher activity attributable to the possible（Fe2＋,Mo6＋） and （Fe3＋,Mo5＋）valency pairs,and the highest activity was observed for Sr2Mg0.2Fe0.8MoO6-δ.The enhancement of the catalytic activity may be correlated with the Fe-relating surface lattice oxygen species and was discussed in view of the presence of oxygen vacancies.
基金Project supported by National Natural Science Foundation of China (20871121)the Science Foundation for Young Scholar of Hanshan Normal University (LQ201001)the Scientific Research Fund for Doctoral Start-up Project of Hanshan Normal University
文摘The VUV-UV spectroscopic properties of Ce3＋ in Ba2Mg（BO3）2,Ba2Ca（BO3）2 and Sr2Mg（BO3）2 were compared,and the relation between the energy of the 4f→5d transition of Ce3＋ and the coordination environments of substituted alkaline earth ions was discussed.The chromaticity coordinates of Ce3＋ activated X2Z（BO3）2（X=Ba,Sr;Z=Ca,Mg） phosphors were changeable from blue to whitish and further to green range by varying the doping concentration of Ce3＋ or the types of substituted alkaline earth ions upon 172 nm excitation.
