FUEL CELL SYSTEM AND METHOD FOR OPERATING FUEL CELL SYSTEM

PROBLEM TO BE SOLVED: To provide a fuel cell system capable of detecting reduction in battery performance due to catalyst poisoning of a fuel cell caused by a sulfur compound. SOLUTION: The fuel cell system 100 includes a fuel cell stack 101, a voltage applying device 102, and a poisoning determination device 120a. The voltage applying device 102 applies a voltage, in which a potential of the other electrode becomes a potential which is lower than a hydrogen redox potential (hereinafter referred to as the first voltage), to a fuel cell, and thereafter, applies a voltage, in which the potential of the other electrode becomes a potential generated on the surface of platinum catalyst by an oxide (hereinafter referred to as the second voltage), to the fuel cell. The poisoning determination device 120a determines that the fuel cell is poisoned when a difference between a current value with the second voltage applied (hereinafter referred to as the second current value) and a current value with the first voltage applied (hereinafter referred to as the first current value) in determining the poisoning of the fuel cell is smaller than that between the second current value and the first current value in the initial stage of the fuel cell. COPYRIGHT: (C)2011,JPO&INPIT