Nano Nexus 2007 Team Profiles: University of Tennessee, Knoxville

Pictured l-r: Jun Mo Kim, Joseph Rajkumar, Myvizhi Esai Selvan, ORNL Director Jeff Wadsworth, Nano Nexus Managing Director Joy Fisher, Junwu Liu.

Team: Fuel Cell Interface
Team Members: Jun Mo Kim, Junwu Liu, Joseph Rajkumar, Myvizhi Esai Selvan
School: University of Tennessee, Knoxville
Faculty Advisor: Dr. David J. Keffer, Associate Professor, Department of Chemical Engineering
Product or Service: A membrane that acts as a molecular sieve and valve that can be used as an interface between the electrode and the Proton Exchange Membrane (PEM) in the Membrane Electrode assembly (MEA) of the hydrogen fuel cell for optimizing the amount of catalyst and more robust water management.

The platinum-alloy catalyst is the heart of the fuel cell. It absorbs the gaseous molecular hydrogen and after splitting the hydrogen into protons and electrons, it sends the electrons into the electrical circuit and the protons across the membrane to the cathode to complete the circuit. This catalyst particle must have access to three phases within the cell: the gas phase, the solid electrode phase and the electrolyte membrane phase.

If every catalyst particle is to contribute to the generation of electricity, then every particle must have access to all three phases. The Fuel Cell Interface team has improved upon the current practice of irregular placement of particles. Together they have designed a nanostructured interface in which each catalyst particle has access to all three phases. This nanostructured interface acts as a molecular sieve to the hydrogen and water by forcing them to take two separate intended paths, and therefore acts as a valve for the water allowing the flow of water in only one direction. This helps in preventing flooding and maintaining the required hydration in the membrane.

The current interface between the electrode and electrolyte in hydrogen fuel cells is composed of an unstructured distribution of platinum-alloy catalyst particles, some of which are located in environments in which they cannot fully contribute to the generation of electricity.

The Fuel Cell Interface team’s product is innovative in that no other conventional fuel cell technology aims at challenging the problem of the catalyst amount and the water management with a single solution, particularly through a nanostructured interface.

Hydrogen fuel cells as an alternative source of energy in the near future will reduce the nation’s dependence on fossil fuels as the primary energy source. Although the hydrogen fuel cycle is potentially sustainable, there are several technological obstacles toward making the hydrogen fuel cycle a reality.

The Fuel Cell Interface team believes it is taking steps towards crossing these obstacles with its new technology that helps to both reduce the amount of catalyst used and ease the water management process, two major barriers for the commercialization of fuel cells.

The Fuel Cell Interface team recently participated in the Nano I2P® Competition at Nano Nexus 2007, a nanotechnology conference hosted by Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, on April 3, 2007. The conference brought together universities, entrepreneurs, and leaders of the nanotechnology industry in an effort to move nanotechnology out of research organizations and into the marketplace.

”This has been a really good experience as a group,” said Joseph Rajkumar, a Ph.D. candidate at the University of Tennessee. “We’ve received helpful feedback, and we’ve been able to see that our technology could actually be feasible in the market.”