FuelCellsWorks

 ABHISHEK SINGH

 This image shows the likely structure of a metal organic framework optimized for storage of hydrogen.

New research by Rice University scientists suggests that a class of material known as metallacarborane could store hydrogen at or better than benchmarks set by the United States Department of Energy (DOE) Hydrogen Program for 2015.

The work could receive wide attention as hydrogen comes into play as a fuel of the future for cars, in fuel cells and by industry.

The new study by Rice theoretical physicist Boris Yakobson and his colleagues, which appears in the online Journal of the American Chemical Society, taps the power of transition metals scandium and titanium to hold a load of hydrogen molecules — but not so tightly that they can’t be extracted.

A matrix made of metallacarboranes would theoretically hold up to 8.8 percent of its weight in hydrogen atoms, which would at least meet and perhaps surpass DOE milestones issued a year ago for cars that would run on hydrogen fuel.

Yakobson, a professor in mechanical engineering and materials science and of chemistry at Rice, said inspiration for the new study came from the development of metallacarboranes, now well-known molecules that combine boron, carbon and metal atoms in a cage-like structure.

“A single metal atom can bind multiple hydrogen molecules,” Yakobson said, “but metals also tend to aggregate. Without something to hold them, they clump into a blob and are useless.”

Abhishek Singh, lead author of the study, a former postdoctoral researcher for Yakobson and now an assistant professor at the Indian Institute of Science in Bangalore, India, calculated that boron clusters would grip the titanium and scandium, which would in turn bind hydrogen. “The metals fit like a gem in a setting, so they don’t aggregate,” Yakobson said. Carbon would link the clusters to form a matrix called a metal organic framework (MOF), which would act like a sponge for hydrogen.

Investigation of various transition metals showed scandium and titanium to have the highest rate of adsorption (the adhesion of transient molecules — like hydrogen — to a surface). Both demonstrate an affinity for “Kubas” interaction, a trading of electrons that can bind atoms to one another in certain circumstances. “Kubas is a special interaction that you often see mentioned in hydrogen research, because it gives exactly the right binding strength,” Yakobson said.

“If you remember basic chemistry, you know that covalent bonds are very strong. You can bind hydrogen, but you cannot take it out,” he said. “And on the other extreme is weak physisorption. The molecules don’t form chemical bonds. They’re just exhibiting a weak attraction through the van der Waals force.

“Kubas interaction is in the middle and gives the right kind of binding so hydrogen can be stored and, if you change conditions — heat it up a little or reduce pressure — it can be taken out. You want the framework to be like a fuel tank.”

Kubas allows for reversible storage of hydrogen in ambient conditions — ranging from well above to well below room temperature — and that would make metallacarborane materials highly attractive for everyday use, Yakobson said. Physisorption of hydrogen by the carbon matrix, already demonstrated, would also occur at a much lower percentage, which would be a bit of a bonus, he said.

Other studies have demonstrated how to make carborane-based MOFs. “That means they can already make three-dimensional frameworks of material that are still accessible to gas. This is very encouraging to us,” Yakobson said. “There are many papers where people analyze a cluster and say, ‘Oh, this will also absorb a hydrogen,’ but that’s not useful. One cluster is nothing.

“But if chemists can synthesize this particular framework with metallacarborane as an element, this may become a reality.”

Arta Sadrzadeh, a graduate student in Yakobson’s lab, is a co-author.

The Robert Welch Foundation and the Department of Energy supported the project.

Read the abstract here: http://pubs.acs.org/doi/abs/10.1021/ja104544s

• German army introduces portable JENNY fuel cells in a new energy network for soldiers
• Flexible all-in-one solution energy includes portable JENNY fuel cell, SFC Power Manager, solar panel, hybrid battery and extensive accessories 
• Solution reduces weight, increases mobility and improves endurance of soldiers in action

Brunnthal/Munich– SFC Energy AG, technology and market leader for mobile and off-grid power solutions based on fuel cells, has received a further serial order from the German army. Through this order, the German army will be introducing the portable JENNY fuel cell into a new energy network for soldiers. The system solution consists of the portable JENNY fuel cell, the SFC Power Manager, a hybrid battery specially tailored to the system, and a solar panel, as well as extensive accessories. As a powerful and flexible electricity supply, the energy network allows operation of widely different power-consumers – e.g. radios, navigational equipment, night-vision equipment, laser range-finders, portable computers, and PDAs – which can be used when stationary and on the march. The order size is around 1 million Euros. The order was received in the third quarter of 2010, and the systems are expected to be delivered before the end of 2010.

With this power supply and management system, SFC is impressively proving its long-term and internationally-excellent expertise in the field of portable energy. This hybrid solution links fuel cells, solar cells, batteries, and intelligent power management in an integrated energy network. It reduces the load of a soldier by up to 80 percent compared to conventional electricity supply solutions. Through the SFC Power Manager, an intelligent voltage converter, almost any device can be flexibly supplied with electricity using available sources, such as fuel cells, solar panels, or batteries. Furthermore, the network also allows different battery types to be charged on the move during operations. The power supply and energy management is fully automatic, practically soundless, emission-free, and almost undetectable.

“With the second serial order from the German army in 2010, SFC is further extending its leadership as the main provider of independent power supplies in the defense area,” said Dr. Peter Podesser, CEO of SFC Energy AG. “This is a significant milestone; we have moved from being a development partner to a product/system supplier. In 2008, SFC won the Wearable Power Prize of the US Ministry of Defense; now our technology has been rolled out in production. The outstanding technology of SFC allows reliable off-grid power supply, significant reduction in weight, and increased flexibility in field operations. It thus contributes to an extended range of operations by military forces, as well as taking into account the new requirements on an international level, and increases the safety of soldiers in operation.”

Assuming successful deployment and the necessary budgetary funds, current user plans show that further demand can be expected over the next three years.

More information at www.sfc.com

About SFC Energy AG
SFC Energy AG (www.sfc.com) is market leader in fuel cell technologies for mobile and off-grid power applications serving the leisure, industrial and defense markets. As one of Germany’s technology pioneers, SFC has won numerous innovation awards. SFC has alliances with leading companies in a wide range of industries.  Unlike most other fuel cell manufacturers, who are in the research and development phase or run subsidized demonstration projects, SFC has shipped about 19,000 fully commercial products to industrial and private end users for more than six years, and has created a convenient fuel cartridge supply infrastructure. SFC is DIN ISO 9001:2008 certified. SFC is based in Brunnthal, Germany, and has a sales and technical service office in the U.S. SFC Energy AG is listed in the Prime Standard on the German stock exchange (WKN 756857).

ANN ARBOR, MICH. – Adaptive Materials was recently awarded the $1.5 million Phase II option of their existing Defense Advanced Research Projects Agency (DARPA) contract to provide 50‐watt solid oxide fuel cells to the U.S. Army. Total DARPA funding for both Phases I and II totals $2.5 million. Specifically, Adaptive Materials would deliver portable power for use by soldiers in the field via fuel cells powered by JP‐8, the Army’s kerosene‐based logistic fuel type.

“We continue to meet the power needs of our armed forces by innovating and delivering the fuel cells needed in the field,” said Michelle Crumm, Adaptive Materials chief business officer.  “Adaptive Materials’ reliable, portable and rugged fuel cells are the benchmark for the military’s future power sources.”

Designed to give the individual warfighter a lightweight, quiet, efficient and reliable power source, Adaptive Materials fuel cells are useful for a variety of portable electronics. Its 50‐watt system can power a range of applications, including laptops, radios, GPS units, and sensors.

”The integration of JP‐8 into fuel cells will lead to higher power systems for unmanned systems, extending their range and operational usefulness,” Crumm added. “More capable unmanned systems help to keep soldiers out of harm’s way, without burdening the soldier with fuel management issues.”

Since the 50‐watt units that Adaptive Materials will deliver are fueled directly with JP‐8, these systems will simply slip into the current operations of soldiers and decrease the reliance on supply convoys that are at risk for attack. JP‐8, a fuel that is similar to commercial diesel and aviation fuel, is used as the prominent fuel on the battlefield. JP‐8 is used in everything from tactical generators and unmanned vehicles to the military’s mine resistant ambush protected (MRAP) vehicles, helicopters, and fighter aircraft.

Adaptive Materials will deliver its fuel cells to the Army Research Laboratory in late 2011 for field-testing.

Ceres Power Holdings plc today successfully demonstrated its integrated, wall-mounted Combined Heat and Power (‘CHP’) product at its fuel cell mass manufacturing facility in Horsham.

The CHP product was demonstrated operating in representative home-like environments including a kitchen and the company’s installer training area. The CHP product used standard boiler connections for gas, water and electricity and was connected to a standard hot water tank and radiator central heating system.

Operating on mains natural gas, the product ran autonomously generating power on demand, exporting and importing electricity to and from the grid as needed and delivered representative domestic hot water and space heating needs, responding to calls for heat from a standard room thermostat.

The CHP product also demonstrated its unique capability for rapid electricity loadfollowing in response to changing electrical loads being switched on and off including lights and various standard domestic appliances.

Peter Bance, Chief Executive Officer, Ceres Power, commented: “Ceres Power demonstrated the unique differentiation of its CHP product; a single wall-mounted unit that can directly replace a conventional boiler and rapidly follow the electrical load. Being able to generate electricity on demand is a valuable differentiator enabled by our unique technology. Low-carbon despatchable power is what the energy world needs. We are now focusing operationally on installing our CHP products in consumers’ homes as part of the commercial field trials in conjunction with British Gas.”