Monolithic Au/CeO₂ nanorod framework catalyst prepared by dealloying for low-temperature CO oxidation

Area of Science:

• Materials Science
• Catalysis
• Nanotechnology

Background:

• Developing efficient catalysts for low-temperature CO oxidation is crucial.
• Ceria (CeO2) based materials are promising supports due to their oxygen storage capacity.
• Gold (Au) nanoparticles exhibit unique catalytic properties.

Purpose of the Study:

• To synthesize and characterize novel monolithic 3D gold/cerium dioxide (Au/CeO2) nanorod frameworks (NFs).
• To evaluate the catalytic performance of these Au/CeO2 NFs for low-temperature CO oxidation.
• To understand the structure-activity relationship and the role of interfacial interactions.

Main Methods:

• Dealloying of melt-spun Al89.7Ce10Au0.3 ribbons to form nanorod frameworks.
• Calcination in oxygen atmosphere to create the active catalyst.
• Characterization using X-ray Photoelectron Spectroscopy (XPS).
• Testing catalytic activity for CO oxidation at low temperatures.

Main Results:

• Monolithic porous Au/CeO2 NFs with high surface area were successfully prepared.
• Small Au clusters/nanoparticles were highly dispersed on CeO2 nanorods, forming numerous contact interfaces.
• The catalyst exhibited high CO oxidation activity, with a complete reaction temperature as low as 91 °C.
• The calcined catalyst showed excellent sintering resistance and enhanced performance compared to dealloyed samples and bare CeO2.

Conclusions:

• The designed Au/CeO2 NF catalyst demonstrates superior performance for low-temperature CO oxidation.
• The enhanced catalytic activity is attributed to the strong interaction between Au clusters and CeO2 nanorods, high dispersion of Au, and presence of oxygen vacancies.
• The material possesses significant sintering resistance, making it a promising candidate for practical applications.