Reduced graphene oxide (RGO)-supported Pd–CeO2 nanocomposites as highly active electrocatalysts for facile formic acid oxidation

Abstract

Stable and efficient electrocatalysts capable of oxidizing a formic acid molecule are highly required to realize direct formic acid fuel cells (DFAFCs) as promising energy conversion sources. Herein, the electrocatalytic activity of Pd–CeO₂ nanocomposites with an average particle size of 5.32 nm dispersed on a reduced graphene oxide (RGO) support, i.e. Pd–CeO₂/RGO, towards the formic acid oxidation reaction (FAOR) was studied. The microstructural and morphological details of the as prepared electrocatalysts were studied by X-ray diffraction, electron microscopy and cyclic voltammetry (CV) techniques. The electrocatalytic activity of the nanoparticles for the FAOR was recorded in a mixed solution of N₂-saturated 0.5 M sulfuric acid and 0.5 M formic acid at room temperature (RT). The Pd–CeO₂/RGO catalyst possesses superior FAOR activity and more stability compared with the prepared Pd/RGO and commercial Pd/C catalysts. The facile fabrication route presented here is capable of being extended to synthesize multifunctional nanocomposites for electrocatalytic applications.