Impurities in fuels and air

Abstract

Despite impressive developments in the technology of proton-exchange membrane fuel cells (PEMFCs), large-scale commercialization still faces issues of low stability and durability that continue to be adversely affected by impurities in the PEMFC system. This article provides a thorough discussion of the impurity and contamination issues that have plagued PEMFC performance. After a brief introduction to the operational principles of the PEMFC, the common sources of impurities in PEMFC systems are discussed, including fuel-side impurities (COx, H2S, and NH3), air-side impurities (NOx, SOx, and COx), and impurities coming from the system components themselves. The effect of contamination and the mechanisms of these impurities on fuel cell operation and performance are presented, followed by a detailed discussion of current strategies for mitigating contamination. Finally, suggestions are provided for future work in PEMFC contamination research.