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

Abstract

Hydrogen peroxide (H2O2), 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 H2O2 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 Ni0.95Ce0.05 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.