The newly discovered material is a high-pressure form of ammonia borane, a solid material which itself is already imbued with ample hydrogen. By working with the parent material at high pressure in an atmosphere artificially enriched with hydrogen, the scientists were able to ratchet up the hydrogen content of the material by roughly 50 percent.
"Including the hydrogen already stored in ammonia borane, this new material can store around 30 weight percent in total," said Yu Lin, lead author of a paper describing the work that was published this week in the online edition of Proceedings of the National Academy of Sciences.
The Department of Energy has set a target for hydrogen-powered vehicles of having an on-board storage system able to store 9 percent, by weight, of hydrogen in 2015. The new compound, called ammonia borane-hydrogen, contains more than triple that amount.
But the fly in the hydrogen is that the sought-after storage system must function at ambient pressure and temperature conditions. The process Lin used to get the added hydrogen into the ammonia borane has to take place at a minimum pressure that is approximately 60,000 times the usual pressure at the surface of the Earth.
"For energy applications, we need to stabilize the material near ambient conditions," said Lin, a graduate student in geological and environmental sciences. Currently, most hydrogen-powered machines use either compressed hydrogen gas or liquid hydrogen, which needs to be maintained at high pressure or very low temperature, respectively, relative to ambient temperature and pressure. These methods have associated safety concerns in the case of compressed hydrogen and require significant energy for cooling in the case of liquid hydrogen.
There is currently no material that satisfies all of the requirements for on-board fuel storage for hydrogen-powered vehicles, according to Lin, who is working with Wendy Mao, assistant professor of geological and environmental sciences at Stanford and a co-author of the paper.
"If the material can be stabilized at or near ambient conditions with a large amount of hydrogen content, then I think it will be very promising," Lin said.
There are potentially several ways to help stabilize the compound under normal temperature and pressure conditions. One idea is that there might be some "alternative chemical paths, like adding some catalyst to try to stabilize the system," Lin said.
If Lin and Mao succeed, ammonia borane could move one step closer to becoming an everyday storage material for hydrogen. Also closer to a reality would be scientists' and environmentalists' dream of powering cars with oxygen from the air and hydrogen from the fuel cell, while pumping out only water from the exhaust pipe.
Ho-kwang Mao, senior staff scientist at the Geophysical Laboratory at the Carnegie Institution of Washington, also participated in the research and is a co-author of the PNAS paper. Wendy Mao is also an assistant professor in the photon science department at SLAC National Accelerator Laboratory at Stanford.
The research was funded by the Department of Energy through the Stanford Institute for Materials and Energy Science.
Louis Bergeron | EurekAlert!
When your car knows how you feel
20.12.2017 | FZI Forschungszentrum Informatik am Karlsruher Institut für Technologie
Did you know how many parts of your car require infrared heat?
23.10.2017 | Heraeus Noblelight GmbH
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.
Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...
16.03.2018 | Event News
13.03.2018 | Event News
08.03.2018 | Event News
16.03.2018 | Earth Sciences
16.03.2018 | Physics and Astronomy
16.03.2018 | Life Sciences