Ultra-thin order–disorder CeO2 nanobelts as the non-carbon support of the PtCu catalyst towards methanol oxidation and oxygen reduction reactions

Abstract

The use of carbon supports in direct methanol fuel cells easily leads to the shedding and poisoning of the Pt catalyst and hence the decrease of catalytic activity. Non-carbon materials have been studied to enhance the metal–support interaction and the catalytic performance. Herein, we explored ultra-thin CeO₂ nanobelts (2D-CeO₂) with the order–disorder structure as the support of the PtCu catalyst. PtCu/2D-CeO₂ shows the highest current density of 37.24 mA cm⁻² toward the methanol oxidation reaction (MOR), and a limiting current density of 4.82 mA cm⁻² towards the oxygen reduction reaction. The order–disorder structure of 2D-CeO₂ generates a high volume of oxygen vacancies and strong metal–support interaction. The Pt⁰ proportion of PtCu/2D-CeO₂ is much higher than that of PtCu/C which increases the active sites. The d-band center of PtCu is lowered which facilitates the adsorption and dissociation of reactants, thereby dramatically boosting the electro-catalytic performance.