FuelCellsWorks

May 14, 2009 — Material scientists at Washington University in St. Louis have developed a technique for a bimetallic fuel cell catalyst that is efficient, robust and two-to-five times more effective than commercial catalysts. The novel technique eventually will enable a cost effective fuel cell technology, which has been waiting in the wings for decades and should give a boost for cleaner use of fuels worldwide.

Sandia National Laboratory

A catalyst made of platinum (above in nanocage form), and paladium has been developed by WUSTL’s Yunan Xia and his collaborators. Tests have shown that the “bimetallic” catalyst outperforms commerical catalysts, which could enable a cost effective fuel cell technology and ultimately provide cleaner fuels worldwide.

Younan Xia, Ph.D., the James M. McKelvey Professor of Biomedical Engineering at WUSTL led a team of scientists at WUSTL and the Brookhaven National Laboratory in developing a bimetallic catalyst comprised of a palladium core or “seed” that supports dendritic platinum branches, or arms, that are fixed on the nanostructure, consisting of a nine-nanometer core and seven-nanometer platinum arms. They synthesized the catalysts by sequentially reducing precursor compounds to palladium and platinum with L-ascorbic acid (that is, Vitamin C) in an aqueous solution. The catalysts have a high surface area, invaluable for a number of applications besides in fuel cells, and are robust and stable.

Xia and his team tested how the catalysts performed in the oxygen reduction reaction process in a fuel cell, which determines how large a current will be generated in an electrochemical system similar to the cathode of a fuel cell. They found that their bimetallic nanodendrites, at room temperature, were two-and-a-half times more effective per platinum mass for this process than the state of the art commercial platinum catalyst and five times more active than the other popular commercial catalyst. At 60 degrees C (the typical operation temperature of a fuel cell), the performance almost meets the targets set by the U.S. Department of Energy.

The Department of Energy has estimated for widespread commercial success the “loading” of platinum catalysts in a fuel cell should be reduced by four times in order to slash the costs. The WUSTL technique is expected to substantially reduce the loading of platinum, making a more robust catalyst that won’t have to be replaced often, and making better use of a very limited and very expensive supply of platinum in the world.

The study was published in the online journal Science.

“There are two ways to make a more effective catalyst,” Xia says. “One is to control the size, making it smaller, which gives the catalyst a higher specific surface area on a mass basis. Another is to change the arrangement of atoms on the surface. We did both. You can have a square or hexagonal arrangement for the surface atoms. We chose the hexagonal lattice because people have found that it’s twice as good as the square one for the oxygen reduction reaction.

“We’re excited by the technique, specifically with the performance of the new catalyst.”

Xia says seeded growth has emerged recently as a good technique for precisely controlling the shape and composition of metallic nanostructures prepared in solutions. And it’s the only technique that allowed Xia and his collaborators to come up with their unconventional shape.

“When you have something this small, the atoms tend to aggregate and that can reduce the surface area,” Xia says. “A key reason our technique works is the ability to keep the platinum arms fixed. They don’t move around. This adds to their stability. We also make sure of the arrangement of atoms on each arm, so we increase the activity.”

Xia and his collaborators are exploring the possibility of adding other noble metals such as gold to the bimetallic catalysts, making them trimetallic. Gold has been shown to oxidize carbon monoxide, making for even more robust catalysts that can resist the poisoning by carbon monoxide — a reduction byproduct of some fuels.

“Gold should make the catalysts more stable, durable and robust, giving yet another level of control,” Xia says.

According to the Environmental Protection Agency, one-third of greenhouse gas emissions in the United States come from oil-based vehicles used for transportation. With oil prices unstable and environmental concerns increasing, many automakers are testing vehicles powered by hydrogen.

Researchers are continually working to replace the fossil fuels we currently depend on to power our vehicles with clean, renewable energy. Hydrogen fuel cells run cleaner than gasoline engines and have zero emissions. In places like Buffalo, NY, where hydroelectric power from Niagara Falls supplies clean, renewable electricity to Oxy Chemical, whose chlorine manufacturing process creates hydrogen as a byproduct; researchers at the Rochester Institute of Technology found the reduction in greenhouse gasses was 85 percent.

Project Driveway is the largest real world test of hydrogen fuel cell vehicles. Over one hundred, hydrogen-powered Chevrolet Equinoxes are currently being used by real consumers to help understand what it will take to bring the vehicles to market.

As part of its ongoing efforts to focus its on core operations, the Board of Directors and group management of Morphic Technologies are reviewing the strategy for Morphic Fuel Cells. This work will lead to a number of changes. Greater emphasis will be placed on market-driven product planning, and the subsidiaries will be given clearer responsibilities. To further strengthen Morphic’s expertise in the area, a Scientific and Industrial Advisory Council has also been established. In addition to the CEO, the Council will consist of the following individuals: Professor Lars Sjunneson, E.ON, Professor Peter Lindblad, Uppsala University, Professor Bengt-Erik Melander, Chalmers, Professor Martin Rudberg, Linköping University and Director Birger Flygare.

The biggest change compared with today concerns the Group’s work on products and technology platforms. The revised strategy stresses the importance of ensuring that there is a clear thread running from market needs through product planning and product development to industrialization and delivery. All product development will be based on clear goals formulated in a technical roadmap and result in products that meet identified market needs.

In concrete terms, this will require a series of changes in the Group’s approach to product development. To improve efficiency, the activities of Helbio (which operates in fuel conversion) will be focused on its core business, and the company will become the Group’s technology center for catalytic converter and reformer technology. Helbio’s core expertise is also applicable to AccaGen’s products (electrolyzers). The affiliated company Exergy will take over responsibility for the industrialization and manufacture of Helbio’s products.

Exergy Fuel Cells’ operations will be focused on the manufacture of complete fuel cell stacks and integration of fuel converters.

The activities of the subsidiary company AccaGen will be reviewed. The company will become a technology center and production of electrolyzers and other components for energy storage may be subject for outsourcing.

To cut down the time to market, a common sales organization has been created that will market all Morphic Fuel Cells products. The organization will serve as the point of contact with customers in all segments.

“The new structure clarifies the various roles in the Group while placing a stronger emphasis on marketing and sales. We will remain at the forefront in the development of new products, but we will do so in a more efficient way. Establishing a clearer division between our development and sales activities will enable us to generate stronger earnings,” Martin Valfridsson, CEO of Morphic Technologies AB, says.

Scientific and Industrial Council

To further strengthen Morphic’s expertise in the area, a Scientific and Industrial Advisory Council has been established. The council’s tasks will be to provide advice in connection with product development in the Group and to present proposals for guidelines governing the Group’s long-term activities going forward. In addition to the CEO, the Council will consist of the following individuals:

• Professor Lars Sjunnesson, E.ON

Lars Sjunnesson is Head of Research and Development at the energy company E.ON, Visiting Professor of Energy Sciences at the Faculty of Engineering at Lund University since 1997 and an Honorary Doctor at the Budapest University of Technology and Economics since 2009. He is also Chairman of Hydrogen Sweden, the European Hydrogen Association and the Executive Committee of IEA Advanced Fuel Cells. On top of this, he is a member of the boards of Elforsk, Svenskt Gastekniskt Center, PATH (Partnership for Advancing the Transition to Hydrogen) and WEC Studies Committee, IEA Expert Group on Science for Energy, European Commission Joint Undertaking FCH Scientific Committee.

• Professor Peter Lindblad, Uppsala University

Peter Lindblad is Professor of Photochemistry and Molecular Science at Uppsala University. Since the 1990s his research has focused on the production of hydrogen from cyanobacteria, or blue-green algae. He is Assistant Coordinator for Solar H2, the biggest project in this field of research worldwide, and combines his research with assignments for the Swedish Energy Authority and the International Energy Agency (IEA), always with a focus on hydrogen.

• Professor Bengt-Erik Melander, Chalmers

Bengt-Erik Melander is Assistant Professor of Engineering Physics at Chalmers University of Technology, where his research focuses on fuel cells. He has taken a particular interest in research into ion transport and diffusion in condensed materials. The research covers a large variety of electrical and thermal characterization methods, primarily for electrolytes in solid and liquid form, as well as also insulator materials. Ion transport is a highly complex process that plays an important role in many natural and biological processes, and that can also be exploited in wide variety of applications: fuel cells, rechargeable batteries, gas sensors, supercapacitors, etc.

• Professor Martin Rudberg, Linköping University

Martin Rudberg is a professor at Linköping University and Associate Professor of Production Economics. His primary research focus is on production strategy and production planning, and he is currently leading a project focusing on how advanced planning systems (APS) can be employed to improve the efficiency of supply chain management. He is Head of Research at the Center for Process Manufacturing and Acting Director of the Center for Production Strategy, and runs his own consulting firm focusing on training and business development in production logistics.

• Director Birger Flygare

Birger Flygare has worked in the automotive, aerospace/defense, IT and telecom industries for over 45 years and on five continents. Over the last 35 years he has held senior positions at Saab-Scania, Allied Chemical, General Electric, English General Electric/Marconi, FFV Aerotech, Ericsson and Telia, and has also served as advisor for product and venture capital firms in Sweden, Europe and the United States. In recent years he has also devoted a lot of time to energy issues, giving many presentations at international symposia.

The Scientific and Industrial Council will evaluate the technical roadmap and product planning based on expected market needs and profitability potential.

Developing the Organization

To improve flexibility, speed up decision-making and streamline the process for achieving the Group’s operational targets, senior management will be reduced to comprise only three functions: the CEO, CFO and Corporate Strategy / IR. Other senior executives will form part of the management team for the parent company, and all members of management will meet for strategy meetings four times a year. In the intervening periods the Director of Market Development and Chief Operating Officer will report to senior management on regular basis.

Leverkusen– Another environmentally focused solution from Mazda – a Norwegian-specification RX-8 Hydrogen RE – was unveiled today at an historic event in Oslo. The vehicle was unveiled as part of a ceremony celebrating the opening of the latest HyNor hydrogen filling stations. With this opening, Norway’s national hydrogen project has taken a major step towards creating an extended hydrogen infrastructure along the 580 km Oslo to Stavanger route.

On hand at the ceremony were the Norwegian Crown Prince and the Norwegian Minister of Transportation, Ms. Liv Signe Navarsete. After the Crown Prince refuelled the car, Ms Navarsete drove the Mazda rotary-engine sports coupe from Oslo to the Drammen station on zero-emission hydrogen. After delivery of this first facelifted version of the RX-8 Hydrogen RE, Mazda will provide more Norwegian-spec vehicles to the HyNor project under commercial lease contracts beginning this summer.

Mazda also leases this environmental, four-seat sports coupe in Japan, but for the HyNor project it has been developed to meet Norwegian and European specifications with left hand drive and a manual transmission. The product of 18 years of Mazda hydrogen fuel research and development, it uses a dual-fuel rotary engine that allows you to switch between using hydrogen or petrol in areas with no hydrogen infrastructure.

This latest unveiling is just one of Mazda’s environmentally-friendly technologies to be introduced as part of its ‘Sustainable Zoom-Zoom’ strategy; and includes such innovative products as next-generation clean diesel engines, and a fuel-saving idle-stop system called i-STOP.

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US scientists have used an inkjet printer to produce large numbers of photoelectrodes in search of the ideal material to split water molecules and release hydrogen.

Hydrogen is in demand as an alternative energy source and a cheap and efficient method of producing it is a desirable goal. Splitting water molecules using sunlight’s energy fits the bill but there is a need for effective photoelectrodes to do this. Some photoelectrodes, such as metal oxide semiconductors, have long-term stability in sunlight but are inefficient at energy conversion; others exhibit high energy conversion efficiencies but are unstable in sunlight. There is a need for materials with both properties and a fast method to find them.

Now, Nathan Lewis and co-workers at the California Institute of Technology, Pasadena, think that they may have found the solution. Lewis used combinatorial chemistry, which allows large numbers of compounds to be produced at once, to make approximately 200 potential photoelectrodes at a time. They mixed metal ion solutions and printed them into 200 wells on glass coated with tin oxide using an inkjet printer. They then heated the solutions on the glass to form mixed metal oxides. The team tested the oxides for their ability to absorb sunlight and convert it into energy in a high-throughput fashion.

This allows a large database of compounds and their properties to be built up quickly and, as Lewis explains, the data could be used to ‘guide exploration of additional sets of materials for desirable activity in photoelectrochemical solar-based water splitting.’

P. Davide Cozzoli, an expert in nanocrystalline semiconductors from the University of Salento, Lecce, Italy, believes this method will ultimately lead to ‘new photocatalytically active semiconductors for cost-effective production of alternative eco-friendly fuel molecules, thus overcoming the inherent limitations of materials available in nature.’

Elizabeth Davies