Nickel-rare earth (Ce, Sm, Dy) alloy electrodes for hydrogen peroxide reduction in direct liquid fuel cells

Abstract

• Nickel-rare earth (Ce, Sm, Dy) alloys (5 and 10 at.% RE) were prepared by arc melting. • Alloys structure, morphology, and composition were characterized by SEM/EDXS and XRPD. • LSV and CA evaluated Ni-RE alloys’ activity for hydrogen peroxide reduction reaction. • HPRR in alkaline media proceeds with 1.7 electrons exchanged at Ni 0.95 Ce 0.05 electrode. • Good performance of Ni 0.95 Ce 0.05 alloy suggests application in direct liquid fuel cells. Hydrogen peroxide (H 2 O 2 ), a reactive oxygen species, is an excellent alternative to oxygen as an oxidant for direct liquid fuel cells (DLFCs). To overcome problems related to scarcity and high cost of commonly used noble metal electrodes, nickel (Ni) and nickel-rare earth (RE = Ce, Sm, Dy) alloys are synthesised and evaluated as electrode materials for H 2 O 2 reduction reaction (HPRR) in alkaline media. These Ni-RE alloys (containing 5 and 10 at.% RE metal) are produced by arc melting and analysed by X-ray diffraction and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy. Voltammetric and chronoamperometric measurements are employed to assess the performance of the Ni-RE alloys for HPRR in 2 M NaOH solution. The Ni 0.95 Ce 0.05 alloy exhibits impressively high catalytic activity for HPRR, with a number of exchanged electrons of 1.7 and activation energy of 38 kJ mol -1 , suggesting its application as cathode material in DLFCs.