While the MEA “stack-up” looks similar, the environment differs:
Fuel cell MEA environment
* Hydrogen + air/oxygen
* Produces water at the cathode
* Needs careful hydration without flooding
* Sensitive to catalyst poisoning
Electrolyser MEA environment
* Water feed and gas generation
* Produces oxygen at the anode and hydrogen at the cathode
* Needs strong bubble removal and water management
* Oxygen-side materials face harsher electrochemical conditions
What that means in practice
* Materials and catalyst choices differ
* Water quality and gas handling requirements differ
* Degradation mechanisms differ
* System BOP design differs (humidification vs separation/drying, etc.)
