Analyses on Declining Performance of PEMFC with Fuel Containing Impurities

This paper covers our investigation into a decline in FC performance resulting from hydrogen fuel containing CO. Several investigations were conducted into the dependence of CO poisoning on types of catalyst using Pt and Pt-Ru alloy. The investigations are summarized as follows: 1) The poisoning prediction formulas and the poisoning estimation coefficient to predict and estimate the performance were derived theoretically. 2) The actual process of CO poisoning was scrutinized by focusing on adsorption of CO and desorption of CO₂ molecules, and changes of several polarizations caused by CO poisoning were estimated. 3) Investigations into the relationship between the CO concentration, operating pressure, operating temperature and the CO poisoning were carried out. If the FC was operated at a high CO concentration, no significant improvement could be expected when using increased pressure, and further, the effects of the operating temperature is almost the same for the two types of catalyst.