Two-Phase Flow Through the PTL of PEM Water Electrolyzer: MRI Experiments and Numerical Modeling Using Phase-Field Theory

Proton Exchange Membrane (PEM) electrolysis is a promising technology for large industrial-scale hydrogen production, but it faces limitations due to mass transport and electrical transfer issues in the anode Porous Transport Layer (PTL). The optimal porosity and pore size of the PTL contributes to efficient water, gas, and electron transport. In this work, the water/gas counter-current flow through the PTL was studied by both experiment and modeling. Magnetic Resonance Imaging (MRI) is utilized to quantify water content within the porous layer during the two-phase flow for different gas and water inlet flow rates. The dependence of the saturation profile and bubble formation on the gas/water flow rates, water channel's orientation, flow direction is studied. To better understand the two-phase flow characteristics in the PTL, the phase-field model based on the Cahn-Hilliard theory for describing a diffuse interface is used to model the water and gas transport over 2D porous layer.