Au/CeO2 hollow nanospheres with enhanced catalytic activity for CO oxidation

摘要

abstract_textpAu/CeO2 hollow nanospheres were successfully synthesized by template method. Carbon spheres (CSs) were employed as the sacrificial templates, which were fabricated by hydrothermal method, and the shell of CeO2 precursor was formed on the surface of CSs through layer-by-layer self-assembled approach. Then, Au nanoparticles were deposited on the shell. Finally, the templates were removed by calcination and Au/CeO2 hollow spheres with hierarchically porous structure were obtained. The samples were characterized by XRD, SEM, TEM, TG-DSC, and BET analysis. The diameters and thickness of the nanospheres were about 250nm and 20nm, respectively. Samples with different loading amounts of Au were prepared and noted as L-Au/CeO2, M-Au/CeO2, and H-Au/CeO2, corresponding to the Au weight percentages of 1.8, 4.2, and 9.3. The specific surface area of L-Au/CeO2 could reach 87.1m(2)/g, higher than that of M-Au/CeO2 (77.8m(2)/g), while M-Au/CeO2 showed the best catalytic activity that CO could be completely converted to CO2 at 81 degrees C. The CeO2, L-Au/CeO2, and M-Au/CeO2 hollow nanospheres showed excellent catalytic stability. Moreover, this method can be easily extended to the synthesis of other metal oxide hollow nanospheres compounded with Au nanoparticles./p/abstract_text