MOF-derived CeO2/Au@SiO2 hollow nanotubes and their catalytic activity toward 4-nitrophenol reduction

Abstract

A novel porous CeO₂/Au@SiO₂ nanocatalyst with a hollow tube structure was fabricated by using a metal–organic framework as the precursor and sacrificial template. The structure of the nanocatalyst was characterized in detail by TEM, XRD, N₂ physical adsorption and XPS. Au nanoparticles with a mean diameter of 4.8 nm were loaded on the Ce-MOF surface because of the strong chemical affinity between Au NPs and carboxylate ions of the Ce-MOF. The pyrolysis of Ce-MOF gave rise to the formation of a mesoporous CeO₂ hollow tube without alteration of the Au size due to the encapsulation by a SiO₂ shell. The as-prepared CeO₂/Au@SiO₂ nanocatalyst exhibited excellent catalytic activity towards 4-nitrophenol reduction. The superior catalytic activity was attributed to the unique and small size of the Au nanoparticles, the mesoporous structure and the strong interaction between the CeO₂ and Au nanoparticles.