| 摘要 |
PURPOSE:To decrease drop in cell output performance by stopping operation of a fuel cell when the voltage of a unit cell drops to a previously set limit value, and passing a hydrophilic functional group removing gas in a cathode from which an oxidizing agent gas is purged. CONSTITUTION:When cell output performance drops by excessive wetting of a cathode catalyst layer 2b during cell operation and voltage of a unit cell reaches a previously set limit value, cell output performance drop is decided to be caused by excess wetting of the catalyst layer 2 and operation of the cell is stopped for a while. Nitrogen gas is supplied to a cathode 3b to purge an oxygen component of an oxidizing agent remaining in the cathode 3b, then hydrogen gas serving as a hydrophilic functional group removing gas is supplied to conduct hydrogen reduction treatment to the cathode 3b. That is, a hydrophilic functional group produced on the surface of carrier carbon in the catalyst layer 2b is reduced and removed. Or, gas or steam which takes hydrophilic property is brought into contact with the cathode 3b. Wettability of the catalyst layer 2b is decreased, and drop in power generation caused by excessive wetting of the catalyst layer 2b is reduced. |
