STUDY OF CO POISONING IN A PHOSPHORIC-ACI D FUEL-CELL USING A SINGLE-CELL WITH MULTIREFERENCE ELECTRODES

The influence of CO poisoning upon a Phosphoric acid fuel cell was stu died using a single cell with twelve-reference electrodes (RHEs). Due to CO poisoning, remarkable and well-balanced potential shift occurred at the fuel outlet area. The potential shift at the fuel outlet area caused current convergence into the fuel outlet area. The increase in current density at the fuel inlet area due to the current convergence enlarges the overvoltage mainly at the cathode side. The voltage loss due to CO poisoning has been believed to be the increase of overvoltag e only at the anode. In the case of a single cell, however, it was fou nd that the increase of overvoltage at the cathode caused by the curre nt convergence into the fuel inlet area is the major part of the volta ge loss. CO-T potential maps were obtained from the data at various CO concentration and temperature. A CO-T potential map of maximum cathod e potential showed clearly that CO poisoning does not increase the cat hode corrosion.