Fueling A Cleaner Future

Matt Weir

Even though he will be the first to admit his current environmentally-minded project “fell in his lap,” James Wilson, now a Northwestern graduate student in the material sciences department, has shown interest in the environment before. As an NU undergrad he participated in Project Wildcat, the freshmen outdoor orientation program that sends incoming students into the woods for a week before the academic year begins.

Maybe all of that clean air got to Wilson, 28, because now he’s part of a Northwestern-based research team investigating fuel cells, an energy conversion technique that is cleaner and more efficient than the internal combustion engine (the type of engine inside an automobile).

The team recently hit a breakthrough in their research, producing the first-ever three-dimensional images of the interior of a fuel cell. These images could help scientists figure out exactly how fuel cells work, improving both performance and economic feasibility of this new technology.

Material sciences and engineering Prof. Scott Barnett, who has worked with fuel cells since 1989, spearheaded the project and put together the team that worked on the project. The team included two scientists from Argonne National Laboratory, Jon M. Hiller and Dean J. Miller, who helped write the paper on the findings that appeared in Nature Materials, a material sciences journal, earlier this month. Eight other researchers from NU, the University of Washington-Seattle and the University of Michigan worked on the project and the paper. The other researchers from NU are material sciences and engineering Prof. Peter Voorhees and graduate students Roberto Mendoza (now at Pacific Northwest National Laboratory) and Worawarit Kobsiriphat.

“There are other groups now that are doing this kind of work, but I think what sets us ahead is our collaborative effort,” Wilson said. Barnett said the study’s value comes from the benefits to the environment that could result from relying more on fuel cells than convention fuels for energy.

“The fuel cell is a cleaner way of using the fuel we have,” Barnett said. “It’s a conversion technique that makes more efficient use of the fuel … and would also produce less CO2, less greenhouse gas and less of a global warming problem.”

A news release from NU’s Science/Engineering Department put it even more succinctly: “fuel cells are like batteries that can be replenished with fresh fuel. It has no moving parts.”

The research team Barnett put together – with Wilson as the lead author of the paper accompanying the research – is specifically researching the solid oxide fuel cell. The fuel cell relies on the interaction between ionized oxygen – oxygen with an electric charge – and the hydrogen reacting inside it. The hydrogen and oxygen fuse to become water, releasing the electric charge from the oxygen to power whatever electric device is connected to the fuel cell. The water is expelled as steam, the waste product of the fuel cell.

“When you use hydrogen as a fuel, you’re just getting water as steam. If you use higher hydrocarbon fuels such as propane or methane, you get carbon dioxide out. But it’s less than you get from burning gasoline now,” Wilson said. “So it’s clean. It’s efficient. The only concern right now is that it’s too expensive. And that’s how it works. If it costs too much people won’t buy it. They’re not interested. That’s the main driving force behind this research: to reduce costs.”

Wilson worked at Barnett’s fuel cell development company, Functional Coating Technologies, for two years before joining the graduate school and working under Barnett on university projects. Barnett founded the company in 2002 to make fuel cells more viable and interesting to commercial companies. Barnett said he hopes the three-dimensional images they’ve produced will help other researchers improve upon fuel cells so they can be manufactured someday.

“Researchers and developers have not had the technology available to measure the structures of fuel cells,” Barnett said. “This is a missing link. Once we understand them we can make them better.”

Technology is an important component of the study. The image the team needs to make a 3-D figure of is only 10 by 10 microns large, about the size of one square thousandth of a millimeter. (For comparison, the human hair is approximately 100 microns wide.)

The only microscope in the Chicago-area powerful enough to take an accurate picture of something so small is a dual-beam instrument at the Argonne laboratory in DuPage County, Ill. The research facility has an electron beam and a focused-ion beam and takes pictures like an MRI.

“We’re using the ion beam to slice away material and the electron beam to take a picture,” Wilson said. “We’re cutting away, taking a picture, cutting away, taking a picture, until we get a series of pictures to put together.”

Barnett and Wilson both said they see this breakthrough in 3-D imaging as only a step toward commercial viability and success of fuel cells, but they both see it as an important step.

“Hopefully, there’s no way to tell,” Wilson said, “but hopefully this is a landmark paper. We’ll see.”

Reach Matt Weir at [email protected]