Alternative Oxidants for High-Power Fuel Cells Studied by Rotating Disk Electrode (RDE) Voltammetry at Pt, Au, and Glassy Carbon Electrodes

Oxygen (O-2) reduction has long been the factor limiting the power density of most fuel cells. Membraneless, microfluidic fuel cells are a promising new fuel cell technology, yet they are affected even more strongly by O-2, as they usually require a dissolved oxidant, and O-2 has minimal solubility in most solvents. Here we offer a detailed, analytical comparison of the performance of previously employed alternative oxidants, H2O2, MnO4-, VO2+, and ClO-, at Pt, Au, and glassy carbon (GC) rotating disk electrodes (RDEs). We also investigated cerium ammonium nitrate (CAN), which has an exceptionally high potential for reduction. Of the oxidants studied, CAN offers the best immediate advantage, but MnO4-, though requiring development efforts, shows the most long-term promise for high-power fuel cells.