Deciphering the catalyst-ionomer interface in fuel cells: Molecular dynamics simulations of local transport properties

Polymer electrolyte fuel cells are a key technology in the race against climate challenge, and while commercial applications are increasingly common, challenges remain in cost, performance, and durability. Most of the issues that prevent full commercialization affect the catalyst layer, the region where the power-generating electrochemical reactions take place, like the oxygen reduction reaction. This layer consists of platinum nanoparticles supported on a carbon material and covered by an ion conducting polymer. Resistance to the transport of oxygen molecules to this layer causes loss of efficiency, especially at a lower platinum surface area. Driving the cost of fuel cells lower by reducing platinum loading and achieving high durability for heavy duty automotive markets both result in lower catalyst surface over the product lifetime and require increased robustness to oxygen transport losses. The small scale of the components in the catalyst layer make it a challenge to study experimentally and computational efforts are crucial at understanding the underlying interactions. To this end, we propose developing a computational model based on molecular dynamics of the platinum/carbon/polymer region to rationalize the factors affecting oxygen transport resistance and to propose design improvements that can reduce power losses and costs in next-generation fuel cells.

Faculty Supervisor:

Erik Kjeang

Student:

Victor Miguel Fernandez Alvarez

Partner:

Ballard Power Systems Inc.

Discipline:

Engineering - mechanical

Sector:

Manufacturing

University:

Simon Fraser University