A Monte Carlo Study on the Effect of Structural and Operating Parameters on the Water Distribution within the Microporous Layer and the Catalyst Layer of PEM Fuel Cells

Liquid water agglomerations in the catalyst layer and microporous layer of PEM fuel cells are simulated with a 3D Monte Carlo model. The simulations are based on real material structures and locally resolved operating conditions. The 3D material images are obtained from advanced experimental techniques capable of nm-scale imaging. The temperature and the relative humidity profiles are provided by a computational fluid dynamics simulation, based on a single channel fuel cell model taking into account all relevant transport and electrochemical processes. The results of this Monte Carlo study confirm the strong dependency of the water saturation in the catalyst layer and microporous layer on the structural parameters and operating conditions, such as: wettability, pore size and local temperature and relative humidity.