Highly efficient oxygen catalyst found: Rechargeable batteries and hydrogen-fuel production could benefit

ScienceDaily (Oct. 28, 2011) — A team of researchers at MIT has found one of the most effective catalysts ever discovered for splitting oxygen atoms from water molecules -- a key reaction for advanced energy-storage systems, including electrolyzers, to produce hydrogen fuel and rechargeable batteries. This new catalyst liberates oxygen at more than 10 times the rate of the best previously known catalyst of its type.

The new compound, composed of cobalt, iron and oxygen with other metals, splits oxygen from water (called the Oxygen Evolution Reaction, or OER) at a rate at least an order of magnitude higher than the compound currently considered the gold standard for such reactions, the team says. The compound's high level of activity was predicted from a systematic experimental study that looked at the catalytic activity of 10 known compounds.

The team, which includes materials science and engineering graduate student Jin Suntivich, mechanical engineering graduate student Kevin J. May and professor Yang Shao-Horn, published their results in Science on Oct. 28.

The scientists found that reactivity depended on a specific characteristic: the configuration of the outermost electron of transition metal ions. They were able to use this information to predict the high reactivity of the new compound -- which they then confirmed in lab tests.

"We not only identified a fundamental principle" that governs the OER activity of different compounds, "but also we actually found this new compound" based on that principle, says Shao-Horn, the Gail E. Kendall (1978) Associate Professor of Mechanical Engineering and Materials Science and Engineering.

Many other groups have been searching for more efficient catalysts to speed the splitting of water into hydrogen and oxygen. This reaction is key to the production of hydrogen as a fuel to be used in cars; the operation of some rechargeable batteries, including zinc-air batteries; and to generate electricity in devices called fuel cells. Two catalysts are needed for such a reaction -- one that liberates the hydrogen atoms, and another for the oxygen atoms -- but the oxygen reaction has been the limiting factor in such systems.

Other groups, including one led by MIT's Daniel Nocera, have focused on similar catalysts that can operate -- in a so-called "artificial leaf" -- at low cost in ordinary water. But such reactions can occur with higher efficiency in alkaline solutions, which are required for the best previously known catalyst, iridium oxide, as well as for this new compound.

Shao-Horn and her collaborators are now working with Nocera, integrating their catalyst with his artificial leaf to produce a self-contained system to generate hydrogen and oxygen when placed in an alkaline solution. They will also be exploring different configurations of the catalyst material to better understand the mechanisms involved. Their initial tests used a powder form of the catalyst; now they plan to try thin films to better understand the reactions.

In addition, even though they have already found the highest rate of activity yet seen, they plan to continue searching for even more efficient catalyst materials. "It's our belief that there may be others with even higher activity," Shao-Horn says.

Jens Norskov, a professor of chemical engineering at Stanford University and director of the Suncat Center for Interface Science and Catalysis there, who was not involved in this work, says, "I find this an extremely interesting 'rational design' approach to finding new catalysts for a very important and demanding problem."

The research, which was done in collaboration with visiting professor Hubert A. Gasteiger (currently a professor at the Technische Universität München in Germany) and professor John B. Goodenough from the University of Texas at Austin, was supported by the U.S. Department of Energy's Hydrogen Initiative, the National Science Foundation, the Toyota Motor Corporation and the Chesonis Foundation.

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The above story is reprinted from materials provided by Massachusetts Institute of Technology. The original article was written by David L. Chandler, MIT News Office.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

J. Suntivich, K. J. May, H. A. Gasteiger, J. B. Goodenough, Y. Shao-Horn. A Perovskite Oxide Optimized for Oxygen Evolution Catalysis from Molecular Orbital Principles. Science, 2011; DOI: 10.1126/science.1212858

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Ionic liquid catalyst helps turn emissions into fuel

ScienceDaily (Oct. 7, 2011) — An Illinois research team has succeeded in overcoming one major obstacle to a promising technology that simultaneously reduces atmospheric carbon dioxide and produces fuel.

University of Illinois chemical and biological engineering professor Paul Kenis and his research group joined forces with researchers at Dioxide Materials, a startup company, to produce a catalyst that improves artificial photosynthesis. The company, in the university Research Park, was founded by retired chemical engineering professor Richard Masel. The team reported their results in the journal Science.

Artificial photosynthesis is the process of converting carbon dioxide gas into useful carbon-based chemicals, most notably fuel or other compounds usually derived from petroleum, as an alternative to extracting them from biomass.

In plants, photosynthesis uses solar energy to convert carbon dioxide (CO2) and water to sugars and other hydrocarbons. Biofuels are refined from sugars extracted from crops such as corn. However, in artificial photosynthesis, an electrochemical cell uses energy from a solar collector or a wind turbine to convert CO2 to simple carbon fuels such as formic acid or methanol, which are further refined to make ethanol and other fuels.

"The key advantage is that there is no competition with the food supply," said Masel, a co-principal investigator of the paper and CEO of Dioxide Materials, "and it is a lot cheaper to transmit electricity than it is to ship biomass to a refinery."

However, one big hurdle has kept artificial photosynthesis from vaulting into the mainstream: The first step to making fuel, turning carbon dioxide into carbon monoxide, is too energy intensive. It requires so much electricity to drive this first reaction that more energy is used to produce the fuel than can be stored in the fuel.

The Illinois group used a novel approach involving an ionic liquid to catalyze the reaction, greatly reducing the energy required to drive the process. The ionic liquids stabilize the intermediates in the reaction so that less electricity is needed to complete the conversion.

The researchers used an electrochemical cell as a flow reactor, separating the gaseous CO2 input and oxygen output from the liquid electrolyte catalyst with gas-diffusion electrodes. The cell design allowed the researchers to fine-tune the composition of the electrolyte stream to improve reaction kinetics, including adding ionic liquids as a co-catalyst.

"It lowers the overpotential for CO2 reduction tremendously," said Kenis, who is also a professor of mechanical science and engineering and affiliated with the Beckman Institute for Advanced Science and Technology. "Therefore, a much lower potential has to be applied. Applying a much lower potential corresponds to consuming less energy to drive the process."

Next, the researchers hope to tackle the problem of throughput. To make their technology useful for commercial applications, they need to speed up the reaction and maximize conversion.

"More work is needed, but this research brings us a significant step closer to reducing our dependence on fossil fuels while simultaneously reducing CO2 emissions that are linked to unwanted climate change," Kenis said.

Graduate students Brian Rosen, Michael Thorson, Wei Zhu and Devin Whipple and postdoctoral researcher Amin Salehi-Khojin were co-authors of the paper. The U.S. Department of Energy supported this work.

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Illinois at Urbana-Champaign.

Journal Reference:

B. A. Rosen, A. Salehi-Khojin, M. R. Thorson, W. Zhu, D. T. Whipple, P. J. A. Kenis, R. I. Masel. Ionic Liquid-Mediated Selective Conversion of CO2 to CO at Low Overpotentials. Science, 2011; DOI: 10.1126/science.1209786

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Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Ionic liquid catalyst helps turn emissions into fuel

ScienceDaily (Oct. 7, 2011) — An Illinois research team has succeeded in overcoming one major obstacle to a promising technology that simultaneously reduces atmospheric carbon dioxide and produces fuel.

University of Illinois chemical and biological engineering professor Paul Kenis and his research group joined forces with researchers at Dioxide Materials, a startup company, to produce a catalyst that improves artificial photosynthesis. The company, in the university Research Park, was founded by retired chemical engineering professor Richard Masel. The team reported their results in the journal Science.

Artificial photosynthesis is the process of converting carbon dioxide gas into useful carbon-based chemicals, most notably fuel or other compounds usually derived from petroleum, as an alternative to extracting them from biomass.

In plants, photosynthesis uses solar energy to convert carbon dioxide (CO2) and water to sugars and other hydrocarbons. Biofuels are refined from sugars extracted from crops such as corn. However, in artificial photosynthesis, an electrochemical cell uses energy from a solar collector or a wind turbine to convert CO2 to simple carbon fuels such as formic acid or methanol, which are further refined to make ethanol and other fuels.

"The key advantage is that there is no competition with the food supply," said Masel, a co-principal investigator of the paper and CEO of Dioxide Materials, "and it is a lot cheaper to transmit electricity than it is to ship biomass to a refinery."

However, one big hurdle has kept artificial photosynthesis from vaulting into the mainstream: The first step to making fuel, turning carbon dioxide into carbon monoxide, is too energy intensive. It requires so much electricity to drive this first reaction that more energy is used to produce the fuel than can be stored in the fuel.

The Illinois group used a novel approach involving an ionic liquid to catalyze the reaction, greatly reducing the energy required to drive the process. The ionic liquids stabilize the intermediates in the reaction so that less electricity is needed to complete the conversion.

The researchers used an electrochemical cell as a flow reactor, separating the gaseous CO2 input and oxygen output from the liquid electrolyte catalyst with gas-diffusion electrodes. The cell design allowed the researchers to fine-tune the composition of the electrolyte stream to improve reaction kinetics, including adding ionic liquids as a co-catalyst.

"It lowers the overpotential for CO2 reduction tremendously," said Kenis, who is also a professor of mechanical science and engineering and affiliated with the Beckman Institute for Advanced Science and Technology. "Therefore, a much lower potential has to be applied. Applying a much lower potential corresponds to consuming less energy to drive the process."

Next, the researchers hope to tackle the problem of throughput. To make their technology useful for commercial applications, they need to speed up the reaction and maximize conversion.

"More work is needed, but this research brings us a significant step closer to reducing our dependence on fossil fuels while simultaneously reducing CO2 emissions that are linked to unwanted climate change," Kenis said.

Graduate students Brian Rosen, Michael Thorson, Wei Zhu and Devin Whipple and postdoctoral researcher Amin Salehi-Khojin were co-authors of the paper. The U.S. Department of Energy supported this work.

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Illinois at Urbana-Champaign.

Journal Reference:

B. A. Rosen, A. Salehi-Khojin, M. R. Thorson, W. Zhu, D. T. Whipple, P. J. A. Kenis, R. I. Masel. Ionic Liquid-Mediated Selective Conversion of CO2 to CO at Low Overpotentials. Science, 2011; DOI: 10.1126/science.1209786

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Catalyst discovery potential has to revolutionize chemical industry

ScienceDaily (Sep. 27, 2011) — University of Alberta Chemistry Professor Steve Bergens and his graduate student Jeremy Johns have discovered a catalyst that has the potential to revolutionise the chemical industry by reducing its environmental footprint, improving efficiency and minimizing risks.

Their findings were published in a top international chemistry journal Angewandte Chemie this month and provide the chemical industry with a potential solution to issues surrounding economics, efficiency and environmental factors.

"Our findings are a game changer that people having been seeking an answer to for decades," said Bergens.

Bergen said researchers have been working for more than 50 years to find a "clean" and stable catalyst that produces little to no waste and also has a capacity to provide multiple turnovers. In February of this year his student Jeremy Johns created such a catalyst in his laboratory.

"After years of producing disappointing results I was thrilled to see the results that came out of this particular experiment," said Dr Bergens.

"The chemical industry is making huge efforts to reduce its environmental footprint and their economists and accountants are also looking to reduce the cost of not just transporting catalyst but improving its efficiency," said Dr Bergens.

He said the February 2011 discovery opens numerous doors to make these things happen for industries ranging from pharmaceuticals to agrochemicals.

"Catalysts are notoriously unstable and challenging to transport, and the waste products the reactions to produce chemicals produce are equally challenging," Bergens added.

John's catalyst only produces hydrogen as a waste, something that is easy to burn off or react to produce water.

Bergens says early indications are the catalyst is not just safe but also efficient. The researchers have pushed the experiment to produce 7000 turnovers for one unit of catalyst.

"We are hugely excited , and the challenge now is to identify exactly how this catalyst is made up and how we can produce it in amounts to further advance this discovery," said Bergens.

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Alberta, via EurekAlert!, a service of AAAS.

Journal Reference:

Jeremy M. John, Steven H. Bergens. Catalyst for the Hydrogenation of Amides to Alcohols and Amines. Angewandte Chemie International Edition, 2011; DOI: 10.1002/anie.201105348

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Catalyst discovery potential has to revolutionize chemical industry

ScienceDaily (Sep. 27, 2011) — University of Alberta Chemistry Professor Steve Bergens and his graduate student Jeremy Johns have discovered a catalyst that has the potential to revolutionise the chemical industry by reducing its environmental footprint, improving efficiency and minimizing risks.

Their findings were published in a top international chemistry journal Angewandte Chemie this month and provide the chemical industry with a potential solution to issues surrounding economics, efficiency and environmental factors.

"Our findings are a game changer that people having been seeking an answer to for decades," said Bergens.

Bergen said researchers have been working for more than 50 years to find a "clean" and stable catalyst that produces little to no waste and also has a capacity to provide multiple turnovers. In February of this year his student Jeremy Johns created such a catalyst in his laboratory.

"After years of producing disappointing results I was thrilled to see the results that came out of this particular experiment," said Dr Bergens.

"The chemical industry is making huge efforts to reduce its environmental footprint and their economists and accountants are also looking to reduce the cost of not just transporting catalyst but improving its efficiency," said Dr Bergens.

He said the February 2011 discovery opens numerous doors to make these things happen for industries ranging from pharmaceuticals to agrochemicals.

"Catalysts are notoriously unstable and challenging to transport, and the waste products the reactions to produce chemicals produce are equally challenging," Bergens added.

John's catalyst only produces hydrogen as a waste, something that is easy to burn off or react to produce water.

Bergens says early indications are the catalyst is not just safe but also efficient. The researchers have pushed the experiment to produce 7000 turnovers for one unit of catalyst.

"We are hugely excited , and the challenge now is to identify exactly how this catalyst is made up and how we can produce it in amounts to further advance this discovery," said Bergens.

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and Google +1:

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Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Alberta, via EurekAlert!, a service of AAAS.

Journal Reference:

Jeremy M. John, Steven H. Bergens. Catalyst for the Hydrogenation of Amides to Alcohols and Amines. Angewandte Chemie International Edition, 2011; DOI: 10.1002/anie.201105348

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

New catalyst will allow commercialization of revolutionary fuel cells

ScienceDaily (June 15, 2011) — Cheap, much lighter than before and allowing for continuous operation -- what traditional batteries can not offer -- direct formic acid fuel cells can revolutionize the portable electronics market. A new catalyst developed at the Institute of Physical Chemistry of the Polish Academy of Sciences will enable a widespread use of fuel cells, researchers say.

You can hardly find a consumer electronics user who would not be irritated by problems with power supply. The batteries run out quickly and require continuous replacements or take a long time charging. Fuel cells could significantly improve the comfort of using electronic devices. Their commercialization, however, is hampered by many technological problems. A new catalyst developed at the Institute of Physical Chemistry of the Polish Academy of Sciences in Warsaw represents a substantial milestone on the way to dissemination of cheap, durable, light and environment friendly fuel cells powered by formic acid.

Fuel cell is a device converting chemical energy into electric power. The current is generated directly due to fuel combustion in the presence of catalysts used on the anode and the cathode of the fuel cell. "Theoretical efficiency of conversion of chemical energy into electric power in the cells can reach even one hundred percent. The best present fuel cells, powered by hydrogen, reach up to 60% in real life. For comparison, the efficiency of low-compression engines is as low as 20%," says Dr Andrzej Borodzinski from the IPC PAS.

The biggest obstacle to dissemination of hydrogen fuels is the storage of hydrogen. The issue turned out to be extremely technologically challenging and still is waiting for satisfactory solutions. An alternative to fuel cells powered by pure hydrogen is the methanol fuel cell technology. Methanol, however, is toxic and the methanol powered fuel cells must be produced with expensive platinum based catalysts. Moreover, methanol fuel cells have low power and are operated at a relatively high and so potentially hazardous temperature (approximately 90°C).

An alternative solution is formic acid fuel cells. In this case, the reactions occur at room temperature, and the efficiency and power of these fuel cells are clearly higher than those for methanol ones. In addition, formic acid is easy to store and transport. To have, however, formic acid fuel cell stable in operation you need an efficient and durable catalyst.

"The catalyst developed by us has initially lower activity then the existing catalysts made of pure palladium. The difference disappears, however, already after two hours of operation. And further it is only better. Our catalyst is stable in operation, whereas the activity of a pure palladium-based catalyst decreases in time," says Dr Borodzinski.

An advantage of the catalyst developed in the IPC PAS, particularly important from the economic point of view, is that it preserves its properties while operated in formic acid of low purity. Such formic acid can be easily produced in large quantities, also from biomass, so the fuel for new fuel cells would be very cheap.

Formic acid produced from biomass would be a fully environment friendly fuel. The reactions involving formic acid in fuel cells generate as products water and carbon dioxide. The latter is, as a matter of fact, a greenhouse gas, but the biomass is obtained from plants which use carbon dioxide for their growth. As a result, formic acid produced from biomass and consumed in fuel cells would not change the content of carbon dioxide in atmospheric air. The risk of natural environment contamination by formic acid is also low.

Formic acid fuel cells would find numerous applications. They would be particularly suitable in portable electronic devices -- mobile phones, laptops or GPS-based devices. They could also be installed as power supply sources in vehicles, from wheelchairs through electric bicycles up to yachts.

At the IPC PAS the research is being undertaken on the first batteries based on formic acid fuel cells. The researchers expect that a prototype of a commercial device should be ready within a couple of years.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Institute of Physical Chemistry of the Polish Academy of Sciences, via AlphaGalileo.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

New catalyst will allow commercialization of revolutionary fuel cells

ScienceDaily (June 15, 2011) — Cheap, much lighter than before and allowing for continuous operation -- what traditional batteries can not offer -- direct formic acid fuel cells can revolutionize the portable electronics market. A new catalyst developed at the Institute of Physical Chemistry of the Polish Academy of Sciences will enable a widespread use of fuel cells, researchers say.

You can hardly find a consumer electronics user who would not be irritated by problems with power supply. The batteries run out quickly and require continuous replacements or take a long time charging. Fuel cells could significantly improve the comfort of using electronic devices. Their commercialization, however, is hampered by many technological problems. A new catalyst developed at the Institute of Physical Chemistry of the Polish Academy of Sciences in Warsaw represents a substantial milestone on the way to dissemination of cheap, durable, light and environment friendly fuel cells powered by formic acid.

Fuel cell is a device converting chemical energy into electric power. The current is generated directly due to fuel combustion in the presence of catalysts used on the anode and the cathode of the fuel cell. "Theoretical efficiency of conversion of chemical energy into electric power in the cells can reach even one hundred percent. The best present fuel cells, powered by hydrogen, reach up to 60% in real life. For comparison, the efficiency of low-compression engines is as low as 20%," says Dr Andrzej Borodzinski from the IPC PAS.

The biggest obstacle to dissemination of hydrogen fuels is the storage of hydrogen. The issue turned out to be extremely technologically challenging and still is waiting for satisfactory solutions. An alternative to fuel cells powered by pure hydrogen is the methanol fuel cell technology. Methanol, however, is toxic and the methanol powered fuel cells must be produced with expensive platinum based catalysts. Moreover, methanol fuel cells have low power and are operated at a relatively high and so potentially hazardous temperature (approximately 90°C).

An alternative solution is formic acid fuel cells. In this case, the reactions occur at room temperature, and the efficiency and power of these fuel cells are clearly higher than those for methanol ones. In addition, formic acid is easy to store and transport. To have, however, formic acid fuel cell stable in operation you need an efficient and durable catalyst.

"The catalyst developed by us has initially lower activity then the existing catalysts made of pure palladium. The difference disappears, however, already after two hours of operation. And further it is only better. Our catalyst is stable in operation, whereas the activity of a pure palladium-based catalyst decreases in time," says Dr Borodzinski.

An advantage of the catalyst developed in the IPC PAS, particularly important from the economic point of view, is that it preserves its properties while operated in formic acid of low purity. Such formic acid can be easily produced in large quantities, also from biomass, so the fuel for new fuel cells would be very cheap.

Formic acid produced from biomass would be a fully environment friendly fuel. The reactions involving formic acid in fuel cells generate as products water and carbon dioxide. The latter is, as a matter of fact, a greenhouse gas, but the biomass is obtained from plants which use carbon dioxide for their growth. As a result, formic acid produced from biomass and consumed in fuel cells would not change the content of carbon dioxide in atmospheric air. The risk of natural environment contamination by formic acid is also low.

Formic acid fuel cells would find numerous applications. They would be particularly suitable in portable electronic devices -- mobile phones, laptops or GPS-based devices. They could also be installed as power supply sources in vehicles, from wheelchairs through electric bicycles up to yachts.

At the IPC PAS the research is being undertaken on the first batteries based on formic acid fuel cells. The researchers expect that a prototype of a commercial device should be ready within a couple of years.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Institute of Physical Chemistry of the Polish Academy of Sciences, via AlphaGalileo.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Splitting water for renewable energy simpler than first thought? Manganese-based catalyst shows promise

ScienceDaily (May 18, 2011) — An international team, of scientists, led by a team at Monash University has found the key to the hydrogen economy could come from a very simple mineral, commonly seen as a black stain on rocks.

Their findings, developed with the assistance of researchers at UC Davis in the USA and using the facilities at the Australian Synchrotron, was published in the journal Nature Chemistry on May 15, 2011.

Professor Leone Spiccia from the School of Chemistry at Monash University said the ultimate goal of researchers in this area is to create a cheap, efficient way to split water, powered by sunlight, which would open up production of hydrogen as a clean fuel, and leading to long-term solutions for our renewable energy crisis.

To achieve this, they have been studying complex catalysts designed to mimic the catalysts plants use to split water with sunlight. But the new study shows that there might be much simpler alternatives to hand.

"The hardest part about turning water into fuel is splitting water into hydrogen and oxygen, but the team at Monash seems to have uncovered the process, developing a water-splitting cell based on a manganese-based catalyst," Professor Spiccia said.

"Birnessite, it turns out, is what does the work. Like other elements in the middle of the Periodic Table, manganese can exist in a number of what chemists call oxidation states. These correspond to the number of oxygen atoms with which a metal atom could be combined," Professor Spiccia said.

"When an electrical voltage is applied to the cell, it splits water into hydrogen and oxygen and when the researchers carefully examined the catalyst as it was working, using advanced spectroscopic methods they found that it had decomposed into a much simpler material called birnessite, well-known to geologists as a black stain on many rocks."

The manganese in the catalyst cycles between two oxidation states. First, the voltage is applied to oxidize from the manganese-II state to manganese-IV state in birnessite. Then in sunlight, birnessite goes back to the manganese-II State.

This cycling process is responsible for the oxidation of water to produce oxygen gas, protons and electrons.

Co-author on the research paper was Dr Rosalie Hocking, Research Fellow in the Australian Centre for Electromaterials Science who explained that what was interesting was the operation of the catalyst, which follows closely natures biogeochemical cycling of manganese in the oceans.

"This may provide important insights into the evolution of Nature's water splitting catalyst found in all plants which uses manganese centres," Dr Hocking said.

"Scientists have put huge efforts into making very complicated manganese molecules to copy plants, but it turns out that they convert to a very common material found in the Earth, a material sufficiently robust to survive tough use."

The reaction has two steps. First, two molecules of water are oxidized to form one molecule of oxygen gas (O2), four positively-charged hydrogen nuclei (protons) and four electrons. Second, the protons and electrons combine to form two molecules of hydrogen gas (H2).

The experimental work was conducted using state-of-the art equipment at three major facilities including the Australian Synchrotron, the Australian National Beam-line Facility in Japan and the Monash Centre for Electron Microscopy, and involved collaboration with Professor Bill Casey, a geochemist at UC Davis.

"The research highlights the insight obtainable from the synchrotron based spectroscopic techniques -- without them the important discovery linking common earth materials to water oxidation catalysts would not have been made," Dr Hocking said.

It is hoped the research will ultimately lead to the development of cheaper devices, which produce hydrogen.

The work was primarily funded by the U.S. National Science Foundation and the U.S. Department of Energy Monash University, the Australian Research Council through the Australian Centre of Excellence for Electromaterials Science, and the Australian Synchrotron.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Monash University.

Journal Reference:

Rosalie K. Hocking, Robin Brimblecombe, Lan-Yun Chang, Archana Singh, Mun Hon Cheah, Chris Glover, William H. Casey, Leone Spiccia. Water-oxidation catalysis by manganese in a geochemical-like cycle. Nature Chemistry, 2011; DOI: 10.1038/nchem.1049

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Splitting water for renewable energy simpler than first thought? Manganese-based catalyst shows promise

ScienceDaily (May 18, 2011) — An international team, of scientists, led by a team at Monash University has found the key to the hydrogen economy could come from a very simple mineral, commonly seen as a black stain on rocks.

Their findings, developed with the assistance of researchers at UC Davis in the USA and using the facilities at the Australian Synchrotron, was published in the journal Nature Chemistry on May 15, 2011.

Professor Leone Spiccia from the School of Chemistry at Monash University said the ultimate goal of researchers in this area is to create a cheap, efficient way to split water, powered by sunlight, which would open up production of hydrogen as a clean fuel, and leading to long-term solutions for our renewable energy crisis.

To achieve this, they have been studying complex catalysts designed to mimic the catalysts plants use to split water with sunlight. But the new study shows that there might be much simpler alternatives to hand.

"The hardest part about turning water into fuel is splitting water into hydrogen and oxygen, but the team at Monash seems to have uncovered the process, developing a water-splitting cell based on a manganese-based catalyst," Professor Spiccia said.

"Birnessite, it turns out, is what does the work. Like other elements in the middle of the Periodic Table, manganese can exist in a number of what chemists call oxidation states. These correspond to the number of oxygen atoms with which a metal atom could be combined," Professor Spiccia said.

"When an electrical voltage is applied to the cell, it splits water into hydrogen and oxygen and when the researchers carefully examined the catalyst as it was working, using advanced spectroscopic methods they found that it had decomposed into a much simpler material called birnessite, well-known to geologists as a black stain on many rocks."

The manganese in the catalyst cycles between two oxidation states. First, the voltage is applied to oxidize from the manganese-II state to manganese-IV state in birnessite. Then in sunlight, birnessite goes back to the manganese-II State.

This cycling process is responsible for the oxidation of water to produce oxygen gas, protons and electrons.

Co-author on the research paper was Dr Rosalie Hocking, Research Fellow in the Australian Centre for Electromaterials Science who explained that what was interesting was the operation of the catalyst, which follows closely natures biogeochemical cycling of manganese in the oceans.

"This may provide important insights into the evolution of Nature's water splitting catalyst found in all plants which uses manganese centres," Dr Hocking said.

"Scientists have put huge efforts into making very complicated manganese molecules to copy plants, but it turns out that they convert to a very common material found in the Earth, a material sufficiently robust to survive tough use."

The reaction has two steps. First, two molecules of water are oxidized to form one molecule of oxygen gas (O2), four positively-charged hydrogen nuclei (protons) and four electrons. Second, the protons and electrons combine to form two molecules of hydrogen gas (H2).

The experimental work was conducted using state-of-the art equipment at three major facilities including the Australian Synchrotron, the Australian National Beam-line Facility in Japan and the Monash Centre for Electron Microscopy, and involved collaboration with Professor Bill Casey, a geochemist at UC Davis.

"The research highlights the insight obtainable from the synchrotron based spectroscopic techniques -- without them the important discovery linking common earth materials to water oxidation catalysts would not have been made," Dr Hocking said.

It is hoped the research will ultimately lead to the development of cheaper devices, which produce hydrogen.

The work was primarily funded by the U.S. National Science Foundation and the U.S. Department of Energy Monash University, the Australian Research Council through the Australian Centre of Excellence for Electromaterials Science, and the Australian Synchrotron.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Monash University.

Journal Reference:

Rosalie K. Hocking, Robin Brimblecombe, Lan-Yun Chang, Archana Singh, Mun Hon Cheah, Chris Glover, William H. Casey, Leone Spiccia. Water-oxidation catalysis by manganese in a geochemical-like cycle. Nature Chemistry, 2011; DOI: 10.1038/nchem.1049

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here