Additive Effects of Anode and Cathode Contamination

At the cathode catalyst layer, the common contaminants include SO, NO, H2S, NH3, VOCs, and ozone. A trace amount of SQc in air can cause a significant performance decrease. Increases in SO concentration accelerate the degradation. This degradation is due to the adsorbed sulfur on the Pt surface produced from SO reduction, which not only poisons the catalyst but also changes the ORR mechanism. The fuel cell performance is only partly recovered after SO contamination. contamination of the cathode catalyst is also concentration- 

The presence of contaminants in both fuel and air results in an additive contamination effect PEMFC performance degradation is the sum of the eathode and the anode degradation. 

Cheng X, Shi Z, Glass N, Zhang L, Zhang J, Song D, et al. A review of PEM hydrogen fuel cell contamination impacts, mechanisms, and mitigation. J Power Sources 2007 165 739-56. 

Mughal A, Li X. Experimental diagnostics of PEM fuel cells. Int J Environ Stud 2006 63 377-89. 

Larminie J, Dicks A. Proton exchange membrane fuel cells. In Fuel cell systems explained. 2nd ed. London John Wiley Sons, 2003 67-120. 

---