Electrode Surface Modification for Cathode Catalysis in Semi-Fuel Cells

摘要

The characterization and use of a palladium and iridium catalyst combination in an aluminum-hydrogen peroxide semi-fuel cell is described. The Pd/Ir combination outperforms palladium alone or iridium alone on the same substrate. Scanning Electron Microscopy (SEM) data of Pd and Ir catalyzed nickel and planar carbon substrates show non-uniform coverage of the nickel substrate but uniform coverage of the carbon substrate. X-ray Photoelectron Spectroscopy (XPS) spectra of Pd alone, Ir alone and the Pd/Ir combination on nickel foil and carbon substrates are inconclusive. The presence of adventitious carbon and perhaps oxygen make interpretation of the spectra inconclusive at this time. Anodic and cathodic efficiency studies using silver foil and Pd/Ir on carbon as catalysts and EB50V aluminum alloy as the anode are reported upon. Operation of the Al-H2O2 semi-fuel cell incorporating a Pd/Ir on carbon cathode at low current densities yielded H2O2 reduction efficiencies in the 60 to 70% range.