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Focusing on Fuel Cells

By Sheila Nason

In the face of mounting energy-related concerns, fuel cell research is a vibrant — and growing — focus at Rensselaer. It is part of Rensselaer’s continuing expansion of its energy-related research.

Gasoline prices soar higher with every Middle Eastern political disturbance, natural disaster, or increase in demand from developing nations. Home-heating costs may force some to choose between food, medicine, and fuel during cold winter months. Increased reliance on dirty coal fills the skies with pollution.

In the face of these and other energy-related concerns, the fuel cell sounds like a too-good-to-be-true pipe dream. A fuel cell is a device that converts the energy in hydrogen into electricity and heat by electrochemical means instead of combustion. Without a doubt, a lot of challenges remain before pollution-free fuel cells can meet our energy demands. But fuel cells are appearing in increasing numbers of specialized applications, and continuing research is making them more practical, reliable, and cost-effective.

At Rensselaer, the fuel cell research thrust stretches across departments and schools, with activities ranging from basic materials research to manufacturing technology to the education of the next generation of researchers and industry leaders. Initiatives include:

Adobe Photoshop ImageDiagram of fuel cell, courtesy of Rensselaer

    * The New York State Center for Polymer Synthesis, where Director Brian Benicewicz has developed a revolutionary high-temperature fuel cell membrane.
    * The Flexible Manufacturing Center, where a multiyear, multimillion-dollar collaboration with PEMEAS Fuel Cell Technologies has resulted in a fully automated pilot manufacturing line.
    * The new Center for Fuel Cell and Hydrogen Research headed by Glenn Eisman, a widely respected fuel cell researcher who is bringing in government and industry contracts to address fundamental materials issues.
    * The New York State Future Energy Systems Center for Advanced Technologies (CAT), which brings Rensselaer into partnership with Cornell and Brookhaven National Laboratories to transfer energy-related technology to industry.  
    * A prestigious National Science Foundation (NSF) $3.2 million IGERT (Integrative Graduate Education and Research Traineeship) grant to educate an interdisciplinary group of doctoral students in fuel cell science and technology.  
    * A $900,000 Department of Energy grant to extend Benicewicz’s membrane technology to other electrochemical devices.

The fuel cell focus is part of Rensselaer’s continuing expansion of its energy-related research. Energy is the most critical issue facing humanity, says Om Nalamasu, Rensselaer’s vice president for research and the director of the Energy CAT. He points out that 6.5 billion people are competing for the Earth’s dwindling supply of fossil fuels. By the year 2050, there will be 8 to 10 billion people, who will be unable to meet their energy needs without major advances in energy conservation and development of reliable and inexpensive renewable energy systems.

Fuel cells have the potential to meet that need. There are several types; Rensselaer is concentrating first on Proton Exchange Membrane (PEM) fuel cells. The heart of these devices is a thin polymer membrane with electrodes on both sides. At the anode electrode, hydrogen is split into protons and electrons. The membrane allows protons to pass through, but blocks electrons, forcing them to go around. This creates a flow of direct current. At the cathode electrode, the electrons recombine with the protons and with oxygen from the air, creating heat and water as the only byproducts. To produce enough energy for most applications, multiple fuel cells are combined in a fuel cell stack.

Jordan Mader, a member of Rensselaer’s new seven-year B.S.-Ph.D. program, has just begun her doctoral program on a research assistantship with Brian Benicewicz, investigating variations of PBI. (Photo by Kris Qua/Rensselaer)

Nalamasu says fuel cell research is a natural focus for Rensselaer, building on the university’s strengths. These include materials science, mechanical and electrical engineering, biotechnology, and nanotechnology. The goal is world-class science that solves real-world problems with multi-disciplinary focus, he says.

Glenn Eisman, director of Rensselaer’s newly formed Center for Fuel Cell and Hydrogen Research, agrees. “I want to continue to focus RPI on the fundamental science and engineering. That’s what we do best,” he says.

The breadth of the basic research being done at Rensselaer is reflected in the majors of the IGERT and other doctoral students working on fuel cell research. The IGERT program, the first in the nation for fuel cells, will support 27 or 28 doctoral students over five years, about six new students will be admitted each year. The first group includes one student in chemical engineering, two in mechanical engineering, one in decision sciences and engineering systems, one in chemistry, and one in materials science and engineering, according to Michael Jensen, the mechanical engineering professor who heads the program.

Starting with the Membrane

Rensselaer’s fuel cell story begins with the membrane developed by Brian Benicewicz, director of the New York State Center for Polymer Synthesis at Rensselaer. He explains that, for years, fuel cell technology has been based on Nafion, a polymer membrane that requires hydration. Since water boils at 100º C, these fuel cells need to operate under that temperature. And the need for constant hydration creates reliability issues. While others were trying to engineer around the problems, he decided on another approach, taking advantage of Rensselaer’s expertise in polymer synthesis.

Adobe Photoshop ImageLakshmi Krishnan, a postdoctoral student, is working on Glenn Eisman’s primary focus to develop new carbon-free electrodes that would eliminate the production of hydrogen peroxide, a compound that currently damages membranes in Nafion-based, low-temperature fuel cells. (Photo by Kris Qua/Rensselaer)

Benicewicz, professor of chemistry and chemical biology, developed a sol gel process that produced a new membrane from polybenzimidzole (PBI). The PBI membranes, which do not require hydration, work reliably and for long periods of time up to 200º C. The PBI research was funded by PEMEAS Fuel Cell Technologies, based in Germany, and Plug Power, a Latham, N.Y., fuel cell company. PEMEAS markets products based on this technology; Plug Power is in development while Benicewicz continues PBI research, finding ways to improve its performance and tailor it to various applications.

Jordan Mader, a member of Rensselaer’s new seven-year B.S.-Ph.D. program, has just begun her doctoral program on a research assistantship with Benicewicz, investigating variations of PBI. She became interested in fuel cells during a high school research program and is excited to be working on technology that she believes will make a difference. “I’m sick of this oil crisis,” she says.

Manufacturing Fuel Cells

Cost is a major challenge for fuel cell technology. To bring down manufacturing costs, PEMEAS turned to Rensselaer’s Flexible Manufacturing Center (FMC). If the widespread commercial use of fuel cells is to become a reality, advances are needed in the enabling manufacturing technologies, says Ray Puffer Jr., center co-director.

The Rensselaer-PEMEAS collaboration produced a pilot automation line for high-temperature Membrane Electrode Assemblies (MEAs) at the company’s Frankfurt, Germany, plant. Until this line opened in 2002, these MEAs were put together by hand. The FMC continues to improve the manufacturing process. IGERT student Tequila Harris, for example, is working on a closed membrane casting system for PEMEAS. Working with Progressive Machine and Design, the FMC also is investigating new, more energy efficient manufacturing processes to produce PEM fuel cell components.

The FMC has recently been awarded a major research equipment grant from the Robotics Industries Association, the result of a proposal authored by Ray Puffer and FMC co-director Steve Derby. The grant, for three new industrial robot systems and supporting equipment, will be used to initiate a new thrust in automated fuel cell stack assembly research. Additional research support will be sought from federal agencies as well as an industry consortium.

Tequila Harris, for example, is working on a closed casting system for PEMEAS.

Fuel Cell Solutions

In fall 2004, Rensselaer established a formal Center for Fuel Cell and Hydrogen Research. Eisman, chief technology officer at Plug Power, became founding director. His charge was to expand research in fuel cell and electrolytic processes, while at the same time initiating collaborations in new areas. In fall 2005, he and Benicewicz began teaching Introduction to Fuel Cell Science and Engineering, a new upper-level and graduate course.

Eisman had gained broad fuel cell experience at Dow Chemical Company and later at Plug Power. He brought instant high-level visibility to the new center. A member of the National Academy of Sciences committee to review the Freedom Car program, he regularly makes keynote and invited presentations at national and international conferences.

A major equipment donation by Plug Power in November 2004 expanded the lab facilities at Rensselaer.

Plug Power’s goal is to produce viable fuel cell solutions, so donations to a first-class research institution like Rensselaer make sense, says Dr. John Elter, Plug Power’s chief technology officer. “Our donations will help build the region’s intellectual property portfolio and its workforce — as well as the capabilities of graduating engineers we might one day look to hire,” he says.

Chris Calabrese, an IGERT student in materials science, is trying to making the plates more stable. (Photos by Kris Qua/Rensselaer)

One element of Eisman’s current research is on bi-polar plates, the rectangular pieces that separate membranes from one another. The goal is to make them lighter, more conductive, more stable mechanically, and less costly.

Lakshmi Krishnan, a postdoctoral student who earned her doctorate in Princeton’s fuel cell program, is working on Eisman’s primary focus to develop new carbon-free electrodes that would eliminate the production of hydrogen peroxide, a compound that currently damages membranes in Nafion-based, low-temperature fuel cells. Chris Calabrese, an IGERT student in materials science, is trying to make the plates more stable.

With Tom Doherty, a new doctoral student who came to Rensselaer in August, Eisman and Professor Jonathan Dordick, the Howard P. Isermann Professor of Chemical and Biological Engineering, will begin applying biotechnology to electrode research, investigating certain enzymes to see if they facilitate peroxide degradation and oxygen reduction.

In addition to the electrode work, Eisman has established a broad range of collaborations on campus. Materials Science and Engineering Professor Linda Schadler is working with him on polymer modeling. Mechanical Engineering Professor Michael Jensen focuses on thermal management, and he and Eisman have done work with the National Institute of Standards and Technology, using neutron images to “see” water in the membrane, electrode, and plate assembly. Eisman also has collaborated with Assistant Chemistry Professor Yvonne Apkula, who uses light-, X-ray-, and neutron-scattering techniques to study membrane structure, and Professors Toh-Ming Lu and Nikhil Koratkar to develop new electrodes using nano-rods developed by Lu and Koratkar. Eisman also is collaborating with Yaron Danon and Bob Block at RPI’s linear accelerator facility to develop an entirely new imaging technique based on oxygen.

In addition, Eisman heads the fuel cell thrust in the New York State Energy Systems CAT led by Nalamasu. This technology transfer program works with New York industries such as MTI MicroFuel Cells of Albany and General Motor’s fuel cell division in Honeoye Falls, as well as Plug Power here in the Capitol Region.

Future Research

With a world reputation in fuel cell membranes well established, Nalamasu says, Rensselaer can now branch out to other fuel cell areas — not just electrodes and biotechnology, but also the whole question of hydrogen extraction, storage, and transportation. Hydrogen issues are perhaps the biggest challenge in making the technology practical.

Fuel cells have not yet broken free from fossil fuels, with most current models using the hydrogen in natural gas or methane. Fuel cells of the future will more likely use solar or wind power to extract hydrogen from water. Another option would be to use power from the grid for electrolysis, an expensive hydrogen source now. But as gasoline prices rise and technology advances, this approach may become more competitive.

A few hydrogen research programs have begun at Rensselaer. The Benicewicz, Eisman, and Kumar team won a nearly $1 million Department of Energy grant for development of other electrochemical concepts for both separation and storage. One nanotechnology program is depositing nanorods of ruthenium on electrodes to greatly increase the efficiency of electrolysis to obtain hydrogen. Another is looking at carbon nanotubes as a means of storing hydrogen or methane.

It may still be a decade or more before fuel cells are reliably providing power for large numbers of homes, businesses, and automobiles. The nation’s research community, however, is marching steadily toward that goal, and Rensselaer is taking a significant place in the parade.

This article was original published in the Fall 2005 Rensselaer Research Reivew and is reprinted with their permission.
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