Catalytic combustion performance of copper manganese catalyst for low concentration ethanol

In addition to the three conventional pollutants (CO, NO_x and HCs) of traditional gasoline vehicles, gasohol vehicle exhausts also contained alcohols and aldehydes which led to photochemical smog and ozone pollution. CuO_x, MnO_x and CuMnO_x catalysts were prepared by the co-precipitation method for catalytic combustion of low-concentration ethanol emitted from gasohol vehicles in cold start. Moreover, the catalysts were characterized by BET nitrogen adsorption-desorption, X-ray diffraction (XRD), hydrogen temperature programmed reduction (H₂-TPR), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results showed that CuMnO_x catalyst had a better low-temperature catalytic activity for low-concentration ethanol. When the reaction temperature was 185 °C, the yield of CO₂ was as high as 86%, better than that of single CuO_x catalyst (about 20%). Meanwhile, CuMnO_x had a higher CO₂ selectivity than MnO_x. The interactions between Cu and Mn altered the texture, structure and oxidation performance of the catalyst, resulting in the changes in the crystal morphology and electronic environment of the catalyst. There were a large number of oxygen defect sites on the surface of CuMnO_x, which was in favour of the adsorption of oxygen molecules, then turning into surface active oxygen species.