Multiscale Modeling of Oxygen Evolution Through Generated Bilayer Porous Transport Layers for PEMWE Performance Improvement

Abstract

Optimization of proton exchange membrane water electrolyzers (PEMWE) has become a focus of researchers looking for a reliable way to generate power. A vital component to PEMWE operation is the porous transport layer (PTL) on the anode side, which is where oxygen is produced. The PTL must allow water access to the catalyst layer and remove oxygen simultaneously. In this work, a previously developed imaging technique is used to generate bilayer PTL structures. A multiscale modeling approach was used to study the effect of a bilayer PTL on oxygen evolution and PEMWE performance. First, a micro scale model was used to predict oxygen transport pathways through different PTL structures. Results showed that the bilayer PTL results in higher oxygen saturation and faster oxygen transport through the PTL. Second, a macro scale model was used to predict performance using bilayer PTLs. Predictions showed potential values between 10 and 20 mV below single layer potential values. This points to the bilayer improving PEMWE operation. Findings from this work show how the addition of a mesoporous layer to a PTL substrate will improve oxygen transport and removal from the catalyst surface, which will improve PEMWE performance.