Pore Structure and Limiting Current Dnesity of LaNi₅ Catalyzed Porous Anode

Abstract

The limiting current density of porous electrode with LaNi₅ catalyst in an alkaline-type H₂-O₂ fuel cell occurs as a consequence of diffusion control of hydroxyl ion to reaction sites in the porous electrode, so that it is greatly influenced by the ratio of Teflon dispersion to LaNi₅ catalyst and the hot-press temperature during preparation.
The cause is attributed to the change in pore structure of the electrode produced by Teflon. It also involves the increase in narrow paths and bottlenecks as a result of the corresponding decrease in pore size and volume.
The addition of aluminum powder to the electrode and its leaching resulted in an increase in pore size and volume and improved the electrode characteristics. A close relationship was found between limiting current density and liquid penetration rate.