Ex-situ investigation of polymer electrolyte membrane fuel cell cathode catalyst durability.

摘要

Polymer Electrolyte Membrane Fuel Cells (PEMFCs) offer a viable alternative to Internal Combustion Engines in automobiles due to higher efficiency and lower greenhouse gas emissions. PEMFCs are electrochemical cells which combine hydrogen and oxygen to produce electricity and water. Durability and cost of fuel cell components and systems are the major obstacles in PEMFC commercialization.;PEMFCs used in automotive applications undergo several operational cycles: start-stop, temperature and idle-to-peak power cycles by which catalyst degradation takes place. The research presented focuses on studying the cathode catalyst durability during potential cycling at different operating conditions. The current investigation employs rotating disc electrode (RDE) to determine changes in electrochemical active surface area (ECSA) at different pH in perchloric and sulfuric acid, potential hold times (5 to 600 sec) and upper potential limits (0.9 to 1.2V) as a function of temperatures (25 to 80°C). The study also examines the long term stability of Pt/C catalyst with potential cycling. Results have shown that the ECSA losses increase with lower pH, longer potential hold times, higher potentials and temperatures.