| CO preferential oxidation?CO-PROX?reaction has been considered as the most effective way to remove trace carbon monoxide in hydrogen rich gases.CuO-CeO2 catalyst was considered as the industrial prospect catalyst because of its good catalytic performance and low cost.Different morphologies show different catalytic properties due to the CuO-CeO2catalyst belongs to the structure-sensitive catalyst.The physicochemical properties of the catalysts were analyzed by controlling the morphology and Mn doping of the CuO/CeO2 catalysts,and combined with SEM,TEM,XRD,H2-TPR,XPS and UV-vis characterizations.CuO/CeO2 catalysts with different morphology were synthesized by a combination of hydrothermal and impregnation methods.Different shape of CeO2 supports will expose different crystal surfaces and interact with CuO.DFT calculation shows that the intersection of?111?and?002?facets has the highest oxygen vacancies.The spheres CuO/CeO2 catalyst has the optimum performance through the experiment and contain more low-price copper species through the wavelet transform spectra of XAFS.CuO-MnOX/CeO2 catalysts were synthesized by one-step hydrothermal methods,manganese and copper elements could into the CeO2 crystal.The doping of manganese can change the interaction between copper and cerium,but excessive addition of manganese can reduce the oxygen vacancies.Therefore,the optimum ratio of copper to manganese was 2:1 through the experiment.Hollow spheres CuO/CeO2 catalysts with up to three shells were synthesized by the hydrothermal method and impregnation method.The structure of the muilt-shelled hollow spheres can increase the contact area between CuO and CeO2.The triple-shelled CuO/CeO2 hollow microspheres generate the biggest BET specific surface area,the smallest particle size with CuO and CeO2 and more effective collisions with both internal and external of spheres,so that it produces the best catalytic performance. |
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