Hierarchical structure based on Au nanoparticles and porous CeO2 nanorods: Enhanced activity for catalytic applications

Porous CeO2/Au/CeO2 nanorod catalyst has been synthesized by using Ce-MOF as sacrificial template. The preparation involves several sequential steps as follows: 1) synthesis of Ce-MOF, 2) anchoring of Au on Ce-MOF, 3) depositing of tiny CeO2 particles on Ce-MOF/Au through hydrothermal reaction; 4) pyrolysis of Ce-MOF to prepare the inner CeO2 support and obtain grain growth of the outmost CeO2 particles. The TEM and XPS result demonstrated similar chemical properties of CeO2 derived from pyrolysis of Ce-MOF template and growth of tiny CeO2 grains. Moreover, Au nanoparticles can be effectively protected from growth of particle size by the surrounding CeO2 particles. The CeO2/Au/CeO2 catalyst exhibits a remarkable higher catalytic activity in comparison with CeO2/Au counterparts toward reduction of 4-nitrophenol to 4-aminophenol by NaBH4.