Novel methods of stabilization of Raney-Nickel catalyst for fuel-cell electrodes

Two new methods of stabilizing Raney-Nickel (Raney-Ni) catalyst for making fuel-cell anodes were studied. In the first method, the catalyst was oxidized with aqueous H2O2 solution, while in the second, oxygen/air (O-2/air) was used in a slurry reactor. Effects of different concentrations of H2O2 (5-25 wt.%) and different pressures (10-20 psig) of gas were investigated. The stabilized catalyst was characterized using BET surface area, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The catalyst was used in fuel-cell anodes and the electrochemical performance was determined in an alkaline half-cell. The results were compared with electrodes prepared using conventionally stabilized catalysts. The hydrogen peroxide-treated catalyst has higher BET surface area and produces electrodes with lower polarization. In addition to this, H2O2 treatment is convenient, fast and needs simple equipment which involves no instrumentation. Use of oxygen in a slurry reactor to stabilize the catalyst is also convenient but electrode performance is relatively poor. (C) 1998 Elsevier Science S.A.