A series of layered mixed oxides La 4BaCu 5-x Mn x O 13+λ ( x =0—5) was prepared, characterized and used as catalysts for NO+CO reaction. It was found that all the samples were single phase having a structure with f...A series of layered mixed oxides La 4BaCu 5-x Mn x O 13+λ ( x =0—5) was prepared, characterized and used as catalysts for NO+CO reaction. It was found that all the samples were single phase having a structure with five layered perovskite. La 4BaCu 2Mn 3O 13+λ showed the highest activity in the title reaction, this could be attributed to the synergetic effect between Cu and Mn. The results of TPR, TPD and excess oxygen investigations confirmed that the Cu ion would be the active center. The displacement of the Cu ion by Mn caused the Cu ion to be more easily reducible and more content of excess oxygen, and it was beneficial to the activity of the catalyst. The reaction mechanism was also proposed.展开更多
Co-precipitation is an important issue in chemical analysis, where it is often undesirable, but in some cases, it can be exploited. The Zn0.5Mn0.5−xLi2xFe2O4 nanomaterials (x = 0.0, 0.1, 0.2, 0.3 and 0.4) wa...Co-precipitation is an important issue in chemical analysis, where it is often undesirable, but in some cases, it can be exploited. The Zn0.5Mn0.5−xLi2xFe2O4 nanomaterials (x = 0.0, 0.1, 0.2, 0.3 and 0.4) was afforded by utilizing co-precipitation method. The structural and optical characteristics were analyzed for the samples employing X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR) and Ultraviolet-visible spectrophotometer (UV-Vis). XRD revealed that the structure of certain nanoparticles is a cubic spinel with space group (Fd-3m) and crystallite size in the scale 124 - 150 nm. Lattice parameter was determined to increments with Li+1 and that may occur due to the larger ionic radius of the Li1+ ion. FTIR spectroscopy confirmed the form of spinel ferrite and explicated the properties of absorption bands approximately 593, 1111, 1385, 1640, 2922 and 3430. The energy band gap was estimated for all samples with diverse ratios and was observed in the range of 2.58 - 2.52 eV.展开更多
文摘A series of layered mixed oxides La 4BaCu 5-x Mn x O 13+λ ( x =0—5) was prepared, characterized and used as catalysts for NO+CO reaction. It was found that all the samples were single phase having a structure with five layered perovskite. La 4BaCu 2Mn 3O 13+λ showed the highest activity in the title reaction, this could be attributed to the synergetic effect between Cu and Mn. The results of TPR, TPD and excess oxygen investigations confirmed that the Cu ion would be the active center. The displacement of the Cu ion by Mn caused the Cu ion to be more easily reducible and more content of excess oxygen, and it was beneficial to the activity of the catalyst. The reaction mechanism was also proposed.
文摘Co-precipitation is an important issue in chemical analysis, where it is often undesirable, but in some cases, it can be exploited. The Zn0.5Mn0.5−xLi2xFe2O4 nanomaterials (x = 0.0, 0.1, 0.2, 0.3 and 0.4) was afforded by utilizing co-precipitation method. The structural and optical characteristics were analyzed for the samples employing X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR) and Ultraviolet-visible spectrophotometer (UV-Vis). XRD revealed that the structure of certain nanoparticles is a cubic spinel with space group (Fd-3m) and crystallite size in the scale 124 - 150 nm. Lattice parameter was determined to increments with Li+1 and that may occur due to the larger ionic radius of the Li1+ ion. FTIR spectroscopy confirmed the form of spinel ferrite and explicated the properties of absorption bands approximately 593, 1111, 1385, 1640, 2922 and 3430. The energy band gap was estimated for all samples with diverse ratios and was observed in the range of 2.58 - 2.52 eV.
