Globin-like mesoporous CeO₂: A CO-assisted synthesis based on carbonate hydroxide precursors and its applications in low temperature CO oxidation

Globin-like mesoporous CeO₂ has been constructed by using a CO-assisted synthetic approach based on hydroxide carbonate precursors, in which CO plays a key role in the formation of the globin-like mesoporous precursors as the carbon source because of its preferential adsorption on Ce³⁺ under the hydrothermal conditions. The formation mechanism and the thermal transformation process from globin-like mesoporous CeCO₃OH to CeO₂ have been investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, BET surface area measurements, thermal analysis, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy and X-ray photoelectron spectroscopy. Rod-like building blocks interconnected by nanoparticles circle around to form each globin-like CeO₂ spheres, leading to the formation of a mesoporous structure. The globin-like mesoporous CeO₂ shows much better performance in CO catalytic oxidation than ordinary CeO₂ nanoparticles obtained by directly calcining cerium nitrate. Moreover, the globin-like mesoporous CeO₂ can act as an ideal matrix for supported catalysts. Metallic Au particles can be well dispersed in the globin-like CeO₂ matrix to form Au/CeO₂ supported catalysts, which exhibit excellent activity for CO oxidation at room temperature.