Abstract
Carbon corrosion is an important degradation mechanism that can impair PEMFC performance through the destruction of catalyst connectivity, collapse of the electrode pore structure, loss of hydrophobic character, and an increase of the catalyst particle size. In this study, carbon corrosion was quantified in situ by measurement of carbon dioxide in the fuel cell exhaust gases through non-dispersive infrared spectroscopy during simulated drive cycle operations consisting of potential cycling with varying upper and lower potential limits. These studies were conducted for three different types of carbon supports. A reduction in the catalyst layer thickness was observed during a simulated drive cycle operation with a concomitant decrease in catalyst layer porosity, which led to performance losses due to increased mass transport limitations. The observed thickness reduction was primarily due to compaction of the catalyst layer, with the actual mass of carbon oxidation (loss) contributing only a small fraction (< 20%). The dynamics of carbon corrosion are presented along with a model that simulates the transient and dynamic corrosion rates observed in our experiments. Accelerated carbon corrosion stress tests are presented and their effects are compared to those observed for the drive cycle test.
| Original language | English |
|---|---|
| Pages (from-to) | F3148-F3160 |
| Journal | Journal of the Electrochemical Society |
| Volume | 165 |
| Issue number | 6 |
| DOIs | |
| State | Published - 2018 |
Funding
Work supported by the Fuel Cell Technologies Office, Office of Energy Efficiency and Renewable Energy, U.S. DOE. The authors thank Nancy Garland (Technology Development Manager), Dimitrios Papageorgopoulos (Fuel Cells Team Leader), and Sunita Satyapal (FCTO Director) for financial support. In addition, we acknowledge Dennis Torraco for assistance with AST testing. Electron microscopy conducted as part of a user proposal at ORNL’s Center for Nanophase Materials Sciences, which is a U.S. DOE, Office of Science User Facility. We would also like to thank Ion Power, New Castle, DE for supplying us with MEAs. Several Accelerated Stress Tests (ASTs) for PEMFC components (e.g. electrocatalyst, catalyst support, membrane) have been developed by the U.S. Department of Energy (DOE), the U.S. DRIVE Fuel Cell Tech Team (FCTT), and the Japan Automobile Research Institute (JARI).34 These ASTs help evaluate materials durability in short time periods and have been used extensively in this study. Primarily, two types of carbon corrosion ASTs that been recommended by the U.S. DRIVE FCTT; 1.2 V cathode potential hold (2007, see Table AI in Appendix)34 and cycling from 1–1.5 V at 500 mV/sec (2013, see Table AII in Appendix)35; have been used in this study.
| Funders | Funder number |
|---|---|
| Japan Automobile Research Institute | |
| Sunita Satyapal | |
| U.S. DOE | Leader |
| U.S. DRIVE Fuel Cell Tech Team | |
| U.S. Department of Energy | |
| Office of Energy Efficiency and Renewable Energy | |
| Fuel Cell Technologies Office |
