Polymer electrolyte fuel cells (PEFCs) are a promising technology for environmentally friendly automobiles, among other applications. However, performance losses due to oxygen transport hindrances in the PEFC’s cathode continue to be an issue in widespread commercialization. This dissertation focuses on the transport of oxygen through the thickness of the PEFC cathode, and the effect of the cat...

Hierarchical nanostructured spherical carbon with hollow macroporous core in combination with mesoporous shell has been explored to support Pt cathode catalyst with high metal loading in proton exchange membrane fuel cell (PEMFC). The hollow core-mesoporous shell carbon (HCMSC) has unique structural characteristics such as large specific surface area and mesoporous volume, ensuring uniform disp...

Synchrotron-based scanning transmission X-ray spectromicroscopy (STXM) was used to characterize the local chemical environment at and around the platinum particles in the membrane (PTIM) which form in operationally tested (end-of-life, EOL) catalyst coated membranes (CCMs) of polymer electrolyte membrane fuel cells (PEM-FC). The band of metallic Pt particles in operationally tested CCM membrane...

Abstract: We study a pore scale model for the catalyst layer on the cathode side of a fuel cell, where hydrogen and oxygen combine at catalyst sites. Our model distinguishes microscopically the phases of rigid structure, electrolyte, pore-space, and catalyst. The oxygen concentration and the protonic potential are described by diffusion equations with reaction terms on the catalyst’s surface. F...

This research adopted the version control system into the model construction for the single chamber aircathode microbial fuel cell (MFC) system, to understand the interrelation of biological, chemical, and electrochemical reactions. The anodic steady state model was used to consider the chemical species diffusion and electric migration influence to the MFC performance. In the cathodic steady st...

The performance of polymer exchange membrane fuel cells is known to be strongly influenced by the electrochemical reactions occurring in the cathode catalyst layer. The dynamics of the elementary reaction steps in the oxygen reduction reaction on platinum based catalysts are investigated to provide a better understanding of the cathode overpotential. We present a new approach using Dynamic Mont...

In the cathode side of a polymer electrolyte fuel cell (PEFC), a micro porous layer (MPL) added between the catalyst layer (CL) and the gas diffusion layer (GDL) plays an important role in water management. In this work, by using both quasi-static and dynamic pore-network models, water and vapor transport in the MPL and GDL has been investigated. We illustrated how the MPL improved water manage...

A pore-scale description of species and charge transport through a bilayer cathode catalyst layer CL of a polymer electrolyte fuel cell using a direct numerical simulation DNS model is presented. Two realizations of the bilayer catalyst layer structure are generated using a stochastic reconstruction technique with varied electrolyte and void phase volume fractions. The DNS calculations predict ...

Anode dry-out is the main mechanism identified to limit operation in an open metallic element (OME) PEFC. The fundamental water transport mechanisms in the OME PEFC were examined in order to engineer further improved performance and higher temperature operation required for efficient heat rejection. Specifically, the net water drag (NWD) was measured over a range of conditions and analyzed with...