Program Pumps Up Fuel Cell Research
As more countries focus on curbing carbon emissions, electric cars powered by hydrogen are becoming an increasingly attractive choice. But the performance of the fuel cells used to convert hydrogen to electrical energy is far from ideal. Now, a new mathematical theory developed by scientists at Case Western Reserve University and Toyota Central R&D Laboratories in Nagakute, Japan, provides a tool for probing the chemical reactions that occur inside fuel cells. The discovery may bring hydrogen-powered cars a step closer to reality.
Chemistry professor Alfred B. Anderson, at Case Western Reserve, has long been using quantum mechanics theory—a theory to explain how molecules behave at the atomic level—to understand chemical reactions. But until recently the computational tools available were not Sufficiently powerful to study those reactions that occur on the surface of electrodes, such as in fuel cells.
In these devices, hydrogen molecules are split into two protons and two electrons at a negative electrode. The electrons pass through a wire and end up at a positively charged electrode, where they split oxygen molecules in half. These oxygens then pair up with protons to create water molecules. Electrical energy is produced in the process.
Platinum particles on the electrodes are commonly used to speed up, or catalyze, otherwise sluggish reactions. But because platinum is expensive and corrodes, researchers have been searching for other metals that can take its place.
Before they can do that, however, they need better tools for understanding the exact steps involved in the hydrogen and oxygen-splitting reactions and for predicting how changing various parameters will affect them. Ryosuke Jinnouchi, a scientist from Toyota Central R&D Laboratories, joined Anderson’s lab to develop such tools.
Anderson had met Yu Morimoto, a group leader at Toyota and a former Case Western Reserve graduate student, at a meeting in 2004. Morimoto “asked whether he could send one of his young scientists to work in my lab for two years,” Anderson recalls. Jinnouchi joined Anderson’s lab in the spring of 2006 and quickly set to work to develop a software program, called Interface 1.0, that combines several different theories for explaining and predicting chemical reactions.
With Interface 1.0, which Anderson makes available to others at no charge, researchers can now start to tease apart the reaction steps at fuel cells’ electrodes. This information can be used to make reactions more efficient and find catalysts that are cheaper, more active and more stable than platinum. “The new theory has great potential for prediction and for guiding experiments,” says Anderson.