Improved Carbon Corrosion and Platinum Dissolution Durability in Automotive Fuel Cell Startup and Shutdown Operation

Three protocols of accelerated startup and shutdown (SU/SD) test were investigated: startup and shutdown with air supply and soak to both anode and cathode (air-SU/SD), hydrogen protected startup and shutdown (H-2-SU/SD), and hydrogen protected startup and shutdown with a load (H-2-SU/SD with a load). The performance losses, electrochemical surface area (ECSA) reduction, and catalyst layer degradation were characterized and compared for these SU/SD protocols. Air-SU/SD protocol showed much more severe performance loss and catalyst layer degradation than hydrogen protected ones, which confirmed the benefits of hydrogen protection. The temperature effect on air-SU/SD was significant in a broad range from 20 degrees C to 70 degrees C, with low temperature greatly reducing the degradation. The mechanism of H-2 protection and load drawn in alleviating carbon corrosion was explained based on reactions and charge conservation during SU/SD. This paper provides comprehensive test data and failure analysis to quantify the benefits of H-2 protection and load drawn and to facilitate future enhancement of system strategies on SU/SD durability.

Automated summary

This study compared the performance losses and catalyst degradation of three accelerated startup and shutdown test protocols, with results showing that hydrogen protection helps alleviate these issues, and within the range of 20 to 70 degrees Celsius, low temperatures can reduce catalyst layer degradation.