Improvement of cathodic reaction of proton exchange membrane fuel cell by ozone

Improvement of the cathodic polarization of proton exchange membrane fuel cell (PEMFC) requires highly active electrodes to facilitate its electrochemical reaction. An alternative way of using higher oxidant gas like ozone has been investigated in this work. It was found that the open circuit voltage (OCV) of H2/O3 fuel cell (1.62 V) was much higher than the conventional H2/O2 fuel cell (1.0 V). Ozone remarkably improves the activation polarization in low current density region. The H2/O3 PEMFC performance was, however, decreased and close to the H2/O2 in high current density range. This point was called the approached current density. By increasing ozone concentration and cell temperature while reducing cathode gas humidity, the increase of approached current density corresponding to the performance improvement was observed.