NOVEL METHODS OF STABILIZATION OF RANEY-NICKEL CATALYST FOR FUEL-CELLELECTRODES

Two new methods of stabilizing Raney-Nickel (Raney-Ni) catalyst for ma king fuel-cell anodes were studied. In the first method, the catalyst was oxidized with aqueous H2O2 solution, while in the second, oxygen/a ir (O-2/air) was used in a slurry reactor. Effects of different concen trations of H2O2 (5-25 wt.%) and different pressures (10-20 psig) of g as were investigated. The stabilized catalyst was characterized using BET surface area, scanning electron microscopy (SEM) and X-ray diffrac tion (XRD). The catalyst was used in fuel-cell anodes and the electroc hemical performance was determined in an alkaline half-cell. The resul ts were compared with electrodes prepared using conventionally stabili zed catalysts. The hydrogen peroxide-treated catalyst has higher BET s urface area and produces electrodes with lower polarization. In additi on to this, H2O2 treatment is convenient, fast and needs simple equipm ent which involves no instrumentation. Use of oxygen in a slurry react or to stabilize the catalyst is also convenient but electrode performa nce is relatively poor. (C) 1998 Elsevier Science S.A.