Monitoring Carbon Corrosion in Anode of a PEM Fuel Cells Under Fuel Starvation Using a Hydrogen Reference Electrode and on-Line Mass Spectrometry

Abstract

Polymer electrolyte membrane fuel cells (PEMFCs) has attracted great attention in transportation and stationary applications with zero emissions and high efficiency compared to conventional combustion engines. However, various factors limit the lifespan of PEMFCs, which remain a major obstacle to large-scale commercialization. In particular, corrosion of the carbon support is one of the main causes of fatal and irreversible deterioration of PEMFCs performance.If the hydrogen fuel supply is insufficient to maintain current demand due to poor water management or fuel depletion at the anode, carbon corrosion may occur on the anode side. In this fuel starvation condition, reactions that take place in place of hydrogen oxidation, such as water electrolysis and oxidation of the carbon support, compensate for the current shortage.The exact deterioration mechanism of PEMFCs in fuel starvation is investigated by simultaneously monitoring the potential behavior from the anode and the exhaust gas using hydrogen reference electrodes and in situ online mass spectrometry. Interestingly, water electrolysis starts at a lower potential range and carbon oxidation occurs at a higher range as an alternative reaction to hydrogen oxidation. Thus, carbon corrosion, which is detrimental to cell performance, can be reduced by extending the duration of the water electrolysis reaction. In this regard, the introductions of the graphitized carbon support and water electrolysis catalyst to the anode are effective in alleviating damage due to fuel starvation by making a dominant alternative reaction to continue electrolysis of water. And this alternative reaction is Monitored with a hydrogen reference electrode and using on-site online mass spectrometry.