The Coupling Of Oxygen Enrichment Process With The Cathode Reaction Of PEM Fuel Cell

Air is commonly used as the oxidizer in the cathode, but the partial pressure of oxygen at atmospheric pressure is about 0.021MPa with the other being mainly inert nitrogen and then lead the voltage loss. This is a main factor which limits the performance improvement of PEMFC.CeO₂ has been found to have fairly high oxygen storage and release capacity and widely used in cleaning automotive exhaust and SOFC to enhance to oxygen transport. In this paper, CeO₂ is added to Pt/C catalyst in the cathode of PEMFC by both sol and impregnation methods and evaluated by appropriate way. The results of TEM and cyclic voltammogram techniques show that: the size, shape, distribution and coverage degree to the catalyst of CeO₂ will be different with the addition methods different. The proton exchange membrane fuel cell performance test shows that the addition of CeO₂ could improve the performance of PEMFC obviously and represent a notable function of oxygen enrichment in the cathode side. The best content of CeO₂ is 1 % when it is added by impregnation method and 3% when it is added by sol method. In the 0.5M H₂SO₄ solution saturated by air, the rotating disk test reveals that the addition of CeO₂ in the catalyst could facilitate the reduction of oxygen obviously, the current of oxygen reduction was raised about 25%. The mechanism of the effect of CeO₂ in the cathode of PEMFC is analyzed.This paper also investigates the effect of the preparation and work condition of electrode on the performance of cell.