Electrode surface modification for cathode catalysis in semi-fuel cells

摘要

The development of a catalyzed substrate toward the reduction of hydrogen peroxide in a semi-fuel cell is described. Long term reproducible performance and cell voltage over a broad range of current densities were studied. Characterization of theelectrocatalyst was performed using Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometer mapping. Electrodeposition was carried out by cyclic voltammetry. A combination of palladium and iridium outperformed palladium, iridium or silveralone as shown by electrode polarization curves and measured cell voltages at various current densities. The Pd/Ir combination was found to be more uniformly distributed on a high density planar carbon substrate than on a nickel substrate. The Pd/Ircombination exhibited clusters and film growth on the nickel substrate with large areas of the substrate uncovered. The carbon substrate was uniformly covered and showed only spherical clusters of fairly uniform size. Semi-fuel cell voltage measurementsover time and at various current densities showed the superior performance of the Pd/Ir combination on the high density carbon substrate without compromising the current density range of operation for the cell.