EFFECT OF PREPARATION METHODS OF CeO2-MnOx MIXED OXIDES ON PREFERENTIAL OXIDATION OF CO IN H2-RICH GASES OVER CuO-BASED CATALYSTS

The CeO2-MnOx mixed oxides were prepared by deposition-precipitation (DP) and surfactant-templated (CB) methods, and then used as the support of CuO/ CeO2-MnOx catalysts. The samples were characterized by means of XRD, BET, H2-TPR, CO-TPD and XPS. Results show that preparation methods of CeO2-MnOx support have a direct effect on the physicochemical properties and catalytic activities of CuO/CeO2-MnOx catalysts for the CO preferential oxidation in H2-rich gases(CO PROX). CuO/CeO2-MnOx (CB) catalyst exhibits higher CO conversion and stability in H2-rich gases than CuO/CeO2-MnOx (DP), with 100% conversion of CO at 140 °C after a temperature cycle, which indicates that CeO2-MnOx (CB) as support of CuO based catalyst is more useful for CO PROX reaction than CeO2-MnOx (DP). Compared with CuO/CeO2-MnOx (DP), there are richer oxygen vacancies and more Mn4+ species on the surface of CuO/CeO2-MnOx (CB), and stronger interaction between CeO2 and MnOx in it. More amounts of active copper species and complicated transfer of electrons density on CuO/CeO2-MnOx (CB) also favour the activity of the catalyst.