The inhibition of electrochemical carbon corrosion in polymer electrolyte membrane fuel cells using iridium nanodendrites

摘要

The addition of Ir-based water electrolysis catalysts to the catalyst layer in polymer electrolyte membrane fuel cells was examined as a promising approach for preventing electrochemical carbon corrosion under severely corrosive conditions. Electrochemical carbon corrosion of membrane electrode assemblies containing different amounts of IrO_2 or shape-controlled Ir dendrite catalysts were characterized using on-line mass spectrometry. In particular, Ir dendrite catalysts possess high activity toward oxygen evolution reactions when compared to IrO_2. As a result, Ir dendrites provided a very effective method of removing water from the catalyst layer. Therefore, the addition of 1wt% Ir dendrite (0.008 mg cm~(-2)) to the catalyst layer of the cathode decreased electrochemical carbon corrosion by 84% at 1.6 V_(NH)e compared with a conventional membrane electrode assembly in the absence of water electrolysis catalysts.