Mohammed Bazaid
(Advisor: Prof. Seung Soon Jang)
will propose a doctoral thesis entitled,
Computational Investigation of Membrane and Catalyst Layer Design for Enhanced Proton and Oxygen Transport in Polymer Electrolyte Membrane Fuel Cells
On
Monday, April 7, 2025 at 12 pm EDT
In-person in MRDC 3515
Committee:
Prof. Seung Soon Jang – School of Material Science and Engineering (advisor)
Prof. Mark D. Losego – School of Material Science and Engineering
Prof. Guoxiang (Emma) Hu – School of Material Science and Engineering
Prof. Shucong Li – School of Material Science and Engineering
Prof. Yu Huang  - Department of Material Science and Engineering at UCLA

Abstract
Polymer electrolyte membrane fuel cells (PEMFCs) rely on efficient proton and oxygen transport for optimal performance, with their functionality highly dependent on the structure and properties of the electrolyte membrane, catalyst layer, and ionomer distribution. In this study, molecular dynamics (MD) simulations are employed to investigate three critical aspects of PEMFCs: the electrolyte membrane nanophase separation, the effect of carbon surface functionalization on water morphology and proton transport, and a novel catalyst layer design aimed at improving mass transport properties.

In the first part of this work, we examine the performance of a short side chain perfluorosulfonic acid (PFSA) membrane as the electrolyte. The degree of nanophase separation between hydrophilic and hydrophobic domains is analyzed under varying temperature and hydration conditions to determine its effect on proton transport. The results provide insights into how phase segregation influences the formation of continuous proton-conducting networks, which are essential for achieving high ionic conductivity in fuel cell membranes. The second part of this study focuses on the impact of oxygen functionalization on carbon surfaces in the catalyst layer. The degree of functionalization is expected to affect water structuring within the ionomer/water phase, where higher oxygen content on the carbon surface may result in increased water retention near the interface. This study investigates the relationship between water morphology and proton transport, assessing how surface hydrophilicity influences the formation of percolated water pathways that facilitate proton conduction. Understanding this interaction is crucial for optimizing ionomer distribution and reducing transport resistances in catalyst layers. Finally, we propose a novel catalyst layer design that eliminates the need for ionomer by covalently functionalizing the carbon surface with benzyl-sulfonate groups. These hydrophilic acid groups are expected to form a thin, stable water layer, creating an alternative proton conduction pathway while improving oxygen mass transport by removing ionomer coverage on the catalyst surface. This approach has the potential to mitigate oxygen transport resistance, enhance proton transport efficiency, and improve overall fuel cell performance.

This thesis provides fundamental insights into the nanoscale interactions governing proton and oxygen transport in PEMFCs, offering potential design strategies for next-generation fuel cell materials. By leveraging molecular simulations, we aim to inform the development of more efficient electrolyte membranes and catalyst layers that overcome key limitations in existing fuel cell technologies