A pioneering "biofuel cell" that produces electricity from ordinary air spiked with small amounts of hydrogen offers significant potential as an inexpensive and renewable alternative to the costly platinum-based fuel cells that have dominated discussion about the "hydrogen economy" of the future, British scientists reported here today.

The research was presented at the week-long 233rd national meeting of the American Chemical Society, the world's largest scientific society.

Fraser Armstrong, Ph.D., described how his research group at Oxford University built the biofuel cell with hydrogenases -- enzymes from naturally occurring bacteria that use or oxidize hydrogen in their metabolism. The cell consists of two electrodes coated with the enzymes placed inside a container of ordinary air with 3 percent added hydrogen.

That is just below the 4 percent danger level at which hydrogen becomes an explosion hazard. The research established for the first time that it is possible to generate electricity from such low levels of hydrogen in air, Armstrong said.

Prototype versions of the cell produced enough electricity to power a wristwatch and other electronic devices. Armstrong foresees advanced versions of the device as potential power sources for an array of other electronic products that only require low amounts of power.

"The technology is immensely developable," Armstrong said. "We are at the tip of a large iceberg, with important consequences for the future, but there is still much to do before this generation of enzyme-based fuel cells becomes commercially viable. The idea of electricity from hydrogen in air, using an oxygen-tolerant hydrogenase is new, although other scientists have been investigating enzymes as electrocatalysts for years. Most hydrogenases have fragile active sites that are destroyed by even traces of oxygen, but oxygen tolerant hydrogenases have evolved to resist attack."

The biofuel cell has a number of advantages over conventional fuel cells, devices that convert the chemical energy in a fuel into electricity without combustion, Fraser explained. A hydrogen fuel cell uses hydrogen and oxygen, producing water as the only waste product. Platinum is the most commonly used catalyst in conventional (proton exchange membrane) fuel cells, making the devices an expensive alternative energy source with sharply limited uses.

As a precious metal, platinum is in short supply, raising questions about the sustainability of platinum-based fuel cell technology. Platinum is more costly than gold, with recent prices topping $1,000 per ounce. In addition, platinum catalysts are easily poisoned or inactivated by carbon monoxide that often exists as an impurity in industrially produced hydrogen. Carbon monoxide can be removed, but that further increases the cost of conventional fuel cells.

Armstrong pointed out that naturally occurring hydrogenase enzymes can be produced at lower cost, with carbon-monoxide poisoning not being a problem. Since the hydrogenases are chemically selective and tolerant, they work in mixtures of hydrogen and oxygen, avoiding the need for expensive fuel-separation membranes required in other types of fuel cells. Hydrogenases also work at about the same rate as platinum-based catalysts.

The biofuel cell uses enzymes from Ralstonia metallidurans (R. metallidurans), an ancient bacterium believed to have been one of the first forms of life on Earth. It evolved 2.5 billion years ago, when there was no oxygen in Earth's atmosphere, and survived by metabolizing hydrogen.

One focus of Armstrong's research is understanding how the active site of the R. metallidurans hydrogenase developed the ability to cope with oxygen as Earth's atmosphere changed. That could enable scientists to adapt the chemistry in the active site -- the working end of the enzyme -- into biofuel cells that are more tolerant of oxygen. In the current version of the cell, the enzyme is not attached tightly to the electrode and the cell runs for only about two days. The researchers also are investigating the use of enzymes from other organisms.

Oxygen may be necessary for life, but it sure gets in the way of making hydrogen fuel cheaply and abundantly from a family of enzymes present in many microorganisms. Blocking oxygen’s path to an enzyme’s production machinery could lead to a renewable energy source that would generate only water as its waste product.

Researchers at the Beckman Institute for Advanced Science and Technology at the University of Illinois at Urbana-Champaign have opened a window by way of computer simulation that lets them see how and where hydrogen and oxygen travel to reach and exit an enzyme’s catalyst site – the H cluster – where the hydrogen is converted into energy.

The Illinois scientists and three colleagues from the National Renewable Energy Laboratory in Golden, Colo., detailed their findings in the September issue of the journal Structure. What they found could help solve a long-standing economics problem. Because oxygen permanently binds to hydrogen in the H cluster, the production of hydrogen gas is halted. As a result, the supply is short-lived.

Numerous microorganisms have enzymes known as hydrogenases that simply use sunlight and water to generate hydrogen-based energy.

“Understanding how oxygen reaches the active site will provide insight into how hydrogenase’s oxygen tolerance can be increased through protein engineering, and, in turn, make hydrogenase an economical source of hydrogen fuel,” said Klaus Schulten, Swanlund Professor of Physics at Illinois and leader of the Beckman’s Theoretical Biophysics Group.

Using computer modeling developed in Schulten’s lab – Nanoscale Molecular Dynamics (NAMD) and Visual Molecular Dynamics (VMD) – physics doctoral student Jordi Cohen created an all-atom simulation model based on the crystal structure of hydrogenase CpI from Clostridium pasteurianum.

This model allowed Cohen to visualize and track how oxygen and hydrogen travel to the hydrogenase’s catalytic site, where the gases bind, and what routes the molecules take as they exit. Using a new computing concept, he was able to describe gas diffusion through the protein and predict accurately the diffusion paths typically taken.

“What we discovered was surprising,” Schulten said. “Both hydrogen and oxygen diffuse through the protein rather quickly, yet, there are clear differences.”

Oxygen requires a bit more space compared with the lighter and smaller hydrogen, staying close to few well localized fluctuating channels. The hydrogen gas traveled more freely. Because the protein is more porous to hydrogen than to oxygen, the hydrogen diffused through the oxygen pathways but also through entirely new pathways closed to oxygen, the researchers discovered.

The researchers concluded that it could be possible to close the oxygen pathways of hydrogenase through genetic modification of the protein and, thereby, increase the tolerance of hydrogenases to oxygen without disrupting the release of hydrogen gas.

Co-authors with Schulten and Cohen were Kwiseon Kim, Paul King and Michael Seibert, all of the National Renewable Energy Laboratory. The National Institutes of Health, National Science Foundation and the U.S. Department of Energy funded the research.

NAMD is a parallel molecular dynamics code designed for high-performance simulation of large biomolecular systems. VMD is a molecular visualization program for displaying, animating and analyzing large biomolecular systems using 3-D graphics.

Dutch researcher Bart de Graaf has developed a solid oxygen carrier, a sort of oxygen sponge. The oxygen from the sponge reacts with hydrogen to produce water. With De Graaf's discovery a lot of energy can be saved during the production of raw materials for plastics.

Hydrogen is released during the conversion of ethane and propane to ethylene and propylene, raw materials for the production of plastics. Using oxygen from a so-called oxygen sponge to convert hydrogen into water saves a lot of energy during the production process.

The oxygen sponge only reacts with the hydrogen released and not with other compounds in the chemical reaction, such as ethane and propane. This allows more starting materials to be converted in one cycle and makes the separation of the starting material and product both easier and cheaper. This new process therefore saves a lot of energy.

Shopping bags, Australian banknotes and many other materials contain the plastics polyethylene or polypropylene. These are made from the raw materials ethylene and propylene. Linking together these raw materials creates a large network of molecules, a plastic.

The majority of ethylene and propylene is made from ethane and propane, produced during the cracking of crude oil. Ethane and propane are converted into ethylene and propylene plus hydrogen in a reactor vessel at a very high temperature.

Unfortunately, this chemical reaction is an equilibrium reaction. This means that although ethylene and propylene are formed, the starting materials are not completely used up in the reaction. The product produced is therefore contaminated. It costs a lot of energy to separate the starting materials and products, and to return the starting materials left to the reactor.

Bart de Graaf developed a process which directly removes one of the products from the equilibrium reaction. Using an oxygen sponge to convert the hydrogen released into water allows the reaction to continue until most of the starting materials have been used up.

The research was funded by the Netherlands Organisation for Scientific Research.

ScienceDaily (Apr. 8, 2009) — The design of efficient systems for splitting water into hydrogen and oxygen, driven by sunlight is among the most important challenges facing science today, underpinning the long term potential of hydrogen as a clean, sustainable fuel. But man-made systems that exist today are very inefficient and often require additional use of sacrificial chemical agents. In this context, it is important to establish new mechanisms by which water splitting can take place.

Now, a unique approach developed by Prof. David Milstein and colleagues of the Weizmann Institute’s Organic Chemistry Department, provides important steps in overcoming this challenge. During this work, the team demonstrated a new mode of bond generation between oxygen atoms and even defined the mechanism by which it takes place. In fact, it is the generation of oxygen gas by the formation of a bond between two oxygen atoms originating from water molecules that proves to be the bottleneck in the water splitting process. Their results have recently been published in Science.

Nature, by taking a different path, has evolved a very efficient process: photosynthesis – carried out by plants – the source of all oxygen on Earth. Although there has been significant progress towards the understanding of photosynthesis, just how this system functions remains unclear; vast worldwide efforts have been devoted to the development of artificial photosynthetic systems based on metal complexes that serve as catalysts, with little success. (A catalyst is a substance that is able to increase the rate of a chemical reaction without getting used up.)

The new approach that the Weizmann team has recently devised is divided into a sequence of reactions, which leads to the liberation of hydrogen and oxygen in consecutive thermal- and light-driven steps, mediated by a unique ingredient – a special metal complex that Milstein’s team designed in previous studies. Moreover, the one that they designed – a metal complex of the element ruthenium – is a ‘smart’ complex in which the metal center and the organic part attached to it cooperate in the cleavage of the water molecule.

The team found that upon mixing this complex with water the bonds between the hydrogen and oxygen atoms break, with one hydrogen atom ending up binding to its organic part, while the remaining hydrogen and oxygen atoms (OH group) bind to its metal center.

This modified version of the complex provides the basis for the next stage of the process: the ‘heat stage.’ When the water solution is heated to 100 degrees C, hydrogen gas is released from the complex – a potential source of clean fuel – and another OH group is added to the metal center.

‘But the most interesting part is the third ‘light stage,’’ says Milstein. ‘When we exposed this third complex to light at room temperature, not only was oxygen gas produced, but the metal complex also reverted back to its original state, which could be recycled for use in further reactions.’

These results are even more remarkable considering that the generation of a bond between two oxygen atoms promoted by a man-made metal complex is a very rare event, and it has been unclear how it can take place. Yet Milstein and his team have also succeeded in identifying an unprecedented mechanism for such a process. Additional experiments have indicated that during the third stage, light provides the energy required to cause the two OH groups to get together to form hydrogen peroxide (H2O2), which quickly breaks up into oxygen and water. ‘Because hydrogen peroxide is considered a relatively unstable molecule, scientists have always disregarded this step, deeming it implausible; but we have shown otherwise,’ says Milstein. Moreover, the team has provided evidence showing that the bond between the two oxygen atoms is generated within a single molecule – not between oxygen atoms residing on separate molecules, as commonly believed – and it comes from a single metal center.

Discovery of an efficient artificial catalyst for the sunlight-driven splitting of water into oxygen and hydrogen is a major goal of renewable clean energy research. So far, Milstein’s team has demonstrated a mechanism for the formation of hydrogen and oxygen from water, without the need for sacrificial chemical agents, through individual steps, using light. For their next study, they plan to combine these stages to create an efficient catalytic system, bringing those in the field of alternative energy an important step closer to realizing this goal.

Participating in the research were former postdoctoral student Stephan Kohl, Ph.D. student Leonid Schwartsburd and technician Yehoshoa Ben-David all of the Organic Chemistry Department, together with staff scientists Lev Weiner, Leonid Konstantinovski, Linda Shimon and Mark Iron of the Chemical Research Support Department.

Prof. David Milstein’s research is supported by the Mary and Tom Beck-Canadian Center for Alternative Energy Research; and the Helen and Martin Kimmel Center for Molecular Design. Prof. Milstein is the incumbent of the Israel Matz Professorial Chair of Organic Chemistry.

If anyone is around midtown this afternoon, super smokin’ Victoria’s Secret angel, Miranda Kerr (AKA Orlando Bloom’s GF) will be doing a meet and greet with fans at the Secret store on Lexington Avenue and 58th St. at 5PM. According to a press release, Miranda will be showing off her world famous cleavage in “a beautiful medley of garden and ballet themes with romantic pastels and silk satin fabrics.” I’m going to be there, so come make me feel like less of a creep by lurking outside of the Victoria’s Secret with me.

Australian driver Molly Taylor enjoyed a fine start to the British Rally Championship campaign with victory amongst the Suzuki Swift Sport Cup runners on the season-opening Bulldog International Rally.

Partnered by Jemma Bellingham in the only all-female crew in the BRC, the 20-year-old came home at the head of the six-strong Suzuki field to claim maximum points on her first outing in the series.

Taylor got the rally off to a good start on SS1, where she was lying in second place, just half a second off Richard Sykes. Not to be beaten, she continued to claw back time from the other crews, setting four fastest times out of only six stages.

“I only arrived in the country three weeks ago and the shakedown stage on Thursday was the first time I'd actually driven the car, so we were in at the deep-end,” she said. “I had no idea about how my pace would match that of the other crews so I was really pleased to be setting some quick times throughout the day.”

Taylor Swift will appear on The Tonight Show With Jay Leno on Thursday (April 2) for an interview and an outdoor performance. Swift will also attend the world premiere of Hannah Montana: The Movie on Thursday in Los Angeles and will perform on the Academy of Country Music (ACM) Awards on Sunday (April 5) in Las Vegas. In related news, Swift recently surpassed 200 million streams on her MySpace page. She's also on the April cover of Allure magazine and will appear on the cover of Seventeen magazine's May issue.

Insider caught up with Stacy Ferguson (a.k.a. Fergie) just before her in-store appearance and signing at Nordstrom at L.A.’s The Grove to promote her new shoe line with Brown Shoe Co. And while the songstress said she hasn’t yet spotted fans wearing her styles, she’s excited to see the designs she helped develop in action. “It will be such a big deal. I think I’ll squeal,” she said. Of course, the Duchess has a lot to be excited about these days: In addition to her new shoe line and her January marriage to actor Josh Duhamel, she’s prepping for the June 9 launch of the new Black Eyed Peas album, “The E.N.D.,” followed by a year-and-a-half-long tour. She also is gearing up for the release of her upcoming film musical “Nine” (currently in post-production), where she met ­— and shared the screen with ­­— her fashion idol, Sophia Loren. “She’s amazing,” Fergie said. “Just watching the way she came to rehearsal every day — she’s always flawless.”

Taylor Tours
Taylor Swift kicks off her “Fearless” concert tour later next month, and the country cutie will be taking some appropriately daring footwear along. Reps for Everybody Footwear told Insider that Swift (and her stylist, of course) asked the Boston-based brand to produce its Fargo boot in metallic gold and silver (sketched at right — samples are still in production) for her on-stage wardrobe. Swift is already a fan of the low-heeled style — Insider’s source said the songbird owns the boot in brown, gray and black, which she wore for her performance with fellow teen queen Miley Cyrus at this year’s Grammy Awards.

Armour Amps Up
Nike has ’em, Adidas has ’em, and now Under Armour seems to be diving further into the athlete spokesperson game. (An occasionally risky endeavor, considering the recent brouhaha over Under Armour’s potential involvement with recruiting at the University of Maryland.) But the brand is plowing ahead: At an advance peek for its fall ’09 cleat-and-trainer combo pack, to be sold with a coordinating receiver’s glove, brand reps told Insider the company was actively looking to add to its spokesperson roster. However, they wouldn’t give up the name of the wide receiver who would be associated with the new fall product. Could this be the first of many such deals for Under Armour? “We’re about speed and power,” Insider’s source said. “As we build our footwear brand, we need to deal with male and female athletes who represent that.”

Taylor Swift, the first Country artist in the 16-year history of the Nielsen BDS chart to have a single reach #1 on the Pop chart, this week scored her 4th #1 Country single. “White Horse,” from her triple-platinum sophomore album Fearless, claims the #1 spot atop the USA Today/Country Aircheck chart (powered by Mediabase), reaching a radio audience of more than 34 million listeners this week alone. Taylor’s run of #1s began in 2007 when “Our Song” spent 6 weeks at #1. Also this week, she surpassed the 200 million mark for music streams on MySpace.

She will also appear on The Tonight Show with Jay Leno for a performance and interview, April 2. Swift will perform a special outdoor set as part of the Tonight Show’s Concert Series. The Tonight Show with Jay Leno airs nationwide on NBC at 11:30 p.m. ET/PT.

She will also take the stage live at the MGM Grand Arena in Las Vegas on April 5 for a very special performance on the Academy of Country Music Awards telecast. The ACM Awards air live on CBS at 8 p.m. ET/delayed PT. Taylor is nominated for Album of the Year (nominated as both artist and producer), Top Female Vocalist and Video of the Year.

While on the West Coast this week, she will attend the premiere of “Hannah Montana: The Movie.” Taylor makes a cameo appearance in the film, performing her original song “Crazier.” She also contributed the song “You’ll Always Find Your Way Back Home” (performed by Hannah Montana) to the film and soundtrack.

Look for Taylor on the cover of the May issue of Seventeen magazine, on newsstands April 7. This is her second Seventeen cover, her first was exactly a year ago – the magazine’s May, 2008 issue. Taylor is featured on the cover of the April issue of Allure, on newsstands now.

Ms. Swift recently returned from a series of sold-out tour dates in Australia, where her Fearless album was recently certified Platinum. Fearless is currently Triple-Platinum in the U.S., has topped Billboard’s Top 200 Albums all-genre sales chart for 11 weeks, and is currently in its 18th week at #1 on the Country Albums Chart. Fearless is Gold in the UK, New Zealand and Norway. Taylor is the #1 best-seller in Australia and the Asia Pacific region, and she holds the #1 position atop the radio airplay charts in the UK, New Zealand, Asia and Australia.

She kicks off her first-ever headlining tour, the TAYLOR SWIFT FEARLESS 2009 TOUR, on April 23 in Evansville, Ind. The tour runs through October and all shows that have been put on sale have sold out within minutes, including an August show at New York’s Madison Square Garden which recently sold out in one minute.