Au/CeO ₂ hollow nanospheres with enhanced catalytic activity for CO oxidation

Abstract Au/CeO ₂ hollow nanospheres were successfully synthesized by template method. Carbon spheres ( CS s) were employed as the sacrificial templates, which were fabricated by hydrothermal method, and the shell of CeO ₂ precursor was formed on the surface of CS s through layer‐by‐layer self‐assembled approach. Then, Au nanoparticles were deposited on the shell. Finally, the templates were removed by calcination and Au/CeO ₂ 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 250 nm and 20 nm, respectively. Samples with different loading amounts of Au were prepared and noted as L‐Au/CeO ₂ , M‐Au/CeO ₂ , and H‐Au/CeO ₂ , corresponding to the Au weight percentages of 1.8%, 4.2%, and 9.3%. The specific surface area of L‐Au/CeO ₂ could reach 87.1 m ² /g, higher than that of M‐Au/CeO ₂ (77.8 m ² /g), while M‐Au/CeO ₂ showed the best catalytic activity that CO could be completely converted to CO ₂ at 81°C. The CeO ₂ , L‐Au/CeO ₂ , and M‐Au/CeO ₂ 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.