An ultra-thin 2D-CeO2 non-carbon support for significantly improving the methanol oxidation and oxygen reduction reactions

Abstract

A direct methanol fuel cell (DMFC) is a promising environmentally friendly energy device, owing to its low emission and high efficiency. Pt/C is the highly efficient catalyst for DMFCs, but Pt is a precious metal, and its weak interaction with a carbon support undermines the structure stability and activity. Herein, two-dimensional ultra-thin cerium oxide (2D-CeO₂) was explored as a non-carbon support of the PtCu alloy catalyst for enhancing the electrocatalytic performance towards methanol oxidation (MOR) and oxygen reaction (ORR) reactions. The carbon-free PtCu/2D-CeO₂ catalysts show much better electro-activity and durability. Pt_0.25Cu/2D-CeO₂ exhibits the highest current density of 29.94 mA cm⁻² toward the MOR, and a comparable activity to PtCu/C towards the ORR. The exceptional properties, combined with the two-dimensional ultra-thin structure and high column of oxygen vacancies of CeO₂, make the PtCu nanoparticles more evenly distributed and more active, significantly improving the activity and durability for the MOR and ORR.