The structure and stability of the anodic electrochemical interface in a high temperature polymer electrolyte membrane fuel cell under reformate feed
| Autor: | Maria K. Daletou, Fotis Paloukis, Alin Orfanidi, Maria Geormezi, Stylianos G. Neophytides, Nivedita Shroti |
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| Rok vydání: | 2015 |
| Předmět: |
Renewable Energy
Sustainability and the Environment Chemistry Analytical chemistry Energy Engineering and Power Technology Proton exchange membrane fuel cell Partial pressure Electrolyte Overpotential Anode Adsorption Ganglion formation Electrical and Electronic Engineering Physical and Theoretical Chemistry Polarization (electrochemistry) |
| Zdroj: | Journal of Power Sources. 285:499-509 |
| ISSN: | 0378-7753 |
| DOI: | 10.1016/j.jpowsour.2015.03.109 |
| Popis: | The effect of reformate H2 mixture composition on Pt/C based high temperature PEMFC anode was thoroughly studied, in order to understand the anode's tolerance under varying CO and steam partial pressures. It is shown that under steam partial pressure over 12 kPa a high overpotential region appears at current densities over 0.3 A/cm2. This negative effect appears in relation to the structure of the electrochemical interface (EI), as this is specified by the amount of H3PO4 (PA) within the anode catalytic layer. As also shown, the sustainable operation of the anode under reformate containing steam and CO as high as 30 kPa and 2 kPa respectively requires significantly lower loadings of PA. This malfunctioning is attributed to the hydrophobic/hydrophilic properties of the Pt/C-PA EI and its modification when water from the gas phase is dissolved in the PA, in combination with the polarization and the adsorption of CO and H2 on Pt surface. These phenomena and the capillary forces within the catalytic layer are responsible for the alternating contraction (ganglia formation and loss of ionic link within the EI) and spreading (thin film formation and well developed EI) of PA, thus giving rise to oscillatory behavior and unstable performance of the anode. |
| Databáze: | OpenAIRE |
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