| Popis: |
A series of CuMnOx/CeO2/Cordierite and CuMnCeOx/Cordierite catalysts prepared by a complex method with citric acid were investigated on the performance of chlorobenzene (CB) oxidation. The effects of the molar ratio of Mn/Cu, transition metal oxide loading, calcination temperature and time were investigated as the main investigation factor on the performance. Meanwhile, XRD, SEM, BET, H2-TPR, O2-TPD and XPS were used to characterize the physicochemical properties of the samples. The results demonstrated that CuMnOx/CeO2/Cordierite catalysts with step-by-step synthesis exhibited high activity (T90 = 350oC) at the Cu/Mn molar ratio of 5:2, because the incorporation of CuO and MnOx formed CuMn2O4 spinel oxide supported on the surface of CeO2. More importantly, CuMnCeOx/Cordierite catalysts prepared by one-step synthesis exhibited the highest oxidation activity (T90 oC) attributed to the low H2 reduction temperature and desorption energy of surface oxygen, and the formed Cu-Mn-O-Ce solid solution and CeO2 favorable promoted the high dispersion of CuMnOx in the supported catalysts. Enhanced oxygen concentration and mobility, abundant oxygen vacancy, high surface areas, and active sites of CuMnCeOx catalysts promoted the desorption of adsorbed Cl, which is associated with superior activity, repeatability, and stability. In addition, the possible oxidation mechanism was described to demonstrate the by-products generation and oxygen transfer of CuMnCeOx catalysts. The excellent performance for CB degradation exhibited a great promising to resolve CVOCs pollution. |
Full text from SpringerLink