AB5-Type Hydrogen Storage Alloys as Catalysts in Hydrogen-Diffusion Electrodes for Novel H2/Hydride//Perovskite/O2 Alkaline Fuel Cells

Abstract

Development of a non-noble-metal catalyst electrode is an important issue in the research and development of fuel cells. The catalytic activity and durability of AB5-type hydrogen storage alloys used in hydrogen-diffusion electrodes for alkaline fuel cells are evaluated. The experiments demonstrate that the activity and stability for hydrogen oxidation is greatly improved if the particle size is decreased from 5−30 to 1−10 μm. This also improves the electrode stability. SEM and XRD analyses show that no disintegration of the smaller catalyst particles is observed in long-term tests. A novel H2/hydride//perovskite/O2 alkaline fuel cell was constructed as a non-noble-metal fuel cell concept. The results showed that both gas-diffusion electrodes had high catalytic activities and good stability. A maximum power density of 54 mW/cm2 was achieved at 120 mA/cm2 when using H2/O2 and 49 mW/cm2 at 100 mA/cm2 when using H2/air.