Researchers discover promising hydrogen storage material

Nov 01, 2011 by Lisa Zyga feature
At a temperature of 298 K and pressure of 100 bar, the new hydrogen material can store hydrogen at a density of 4.6 wt. %. The inset shows the geometry of a Sc-Pc sheet. Image credit: Kun Lü, et al.

(PhysOrg.com) -- If hydrogen is to ever to serve as an onboard energy carrier for the transportation industry, a material will be needed that can store large amounts of hydrogen at ambient temperature and pressure. So far, researchers have not found any material that can meet these requirements. But in a new study, a team from China and the US has taken a significant step toward this goal by identifying a material that can store hydrogen with a density as high as 4.6 wt. % (i.e., the hydrogen accounts for 4.6% of the total weight of the storage material), enabling it to meet the target of 4.3 wt. % set by the US department of Energy for 2010.

The researchers, led by Qiang Sun from Peking University in Beijing, China, and Virginia Commonwealth University in the Richmond, Virginia, US, have published their study in a recent issue of .

storage is a big challenge for the hydrogen economy,” Sun told PhysOrg.com. “Currently the research is behind schedule, but with the advancement of materials design and synthesis, reaching the for future transportation applications [is becoming] more and more promising.”

As the researchers explained, the greatest difficulty in finding a sufficient hydrogen for onboard storage systems lies in meeting multiple requirements with a single material. For example, in previous studies researchers have found that light metal hydrides can store hydrogen with a gravimetric of 20 wt. %, but the material is not reversible, meaning it cannot be reused. Also, the hydrogen desorbs only at very high temperatures. In contrast, other materials such as carbon nanotubes and metal or covalent organic frameworks can store hydrogen reversibly, but the hydrogen adsorbs only at very low temperatures. The difference is due to bonding: in light metal hydrides, hydrogen is held in much stronger bonds than in the second group of materials. The researchers explain that, ideally, hydrogen should be bound with an intermediate binding energy.

“If the bonding is too strong, hydrogen can only be released at high temperature, while if the bonding is too weak, the storage is unstable at room temperature,” Sun explained. “So we require an intermediate bonding energy.”

In the current study, the researchers used modeling and simulations to investigate the performance of hydrogen storage in metal-containing porous sheets, which can be synthesized using the techniques previously proposed by two other groups (M. Abel, et al., and A. Sperl, et al.). In those techniques, porous sheets were made of blue-green dye units called phthalocyanines (Pc) with regularly spaced iron (Fe) atoms or other metal atoms. Due to their high dispersion, these metal sites in the porous substrates provide the possible adsorption sites for hydrogen molecules.

“Transition metal atoms easily aggregate to form clusters,” Sun said. But materials in which metal atoms can be prevented from coalescing are scarce.

The researchers systematically investigated 10 Pc-based porous sheets with transition from scandium (Sc) through zinc (Zn), and found that porous Pc sheets with Sc atoms could store up to 4.6 wt. % hydrogen. In addition to the Sc atoms’ regular distribution in the Pc sheet, Sc has two other attractive features. First, it is lighter than other transition elements, allowing the overall storage material to be relatively light. Second, Sc atoms have a large size, so that they stick out and can capture more hydrogen molecules.

By theoretically demonstrating that this Sc-Pc porous sheet can be used to create a hydrogen storage material with attractive properties, the researchers hope that the results will stimulate further analysis and experimental tests of the promising material.

Explore further: Synthesis of a new lean rare earth permanent magnetic compound superior to Nd2Fe14B

More information: Kun Lü, et al. “Sc-phthalocyanine sheet: Promising material for hydrogen storage.” Applied Physics Letters 99, 163104 (2011). DOI:10.1063/1.3653465

4.4 /5 (14 votes)

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User comments : 22

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rawa1
2.3 / 5 (3) Nov 01, 2011
What is the price of this material? The cost of phtalocyanine dye is US $1-10 / kg and the cost of scandium is US $70.000 / kg as of 2005...
Cave_Man
1 / 5 (1) Nov 01, 2011
I thought UnitedNuclear.com already had a tank design that was more than adequate using some type of lithium hydride or whatever. They say it works great and 4 tanks are enough to power a vehicle for 200 miles. Also it just needs to be heated a little bit to release the hydrogen, sounds perfect if its true. They seem pretty legit and have been around for years and years (and harassed by the fed and states for years and years)
Isaacsname
1 / 5 (1) Nov 01, 2011
Hell, I heard a rumor a while back that UN got shut down...
arofibook
3.7 / 5 (3) Nov 01, 2011
Promising hydrogen storage material my ass!

I swear there's a "promising hydrogen storage material" every week. And nothing has ever come if it.
Graeme
not rated yet Nov 02, 2011
Instead of %H by weight it should be measuring energy storage by weight and or volume. Expect that a lithium battery will have a higher performance. But a pure hydrogen tank will outscore on weight and lose on volume.
Fedot
1 / 5 (1) Nov 02, 2011
Fuck Hydrogen! Aluminium is way to go. Nice recyclable energy-holder. And you can spike aluminium with hydrogen too!
Ricochet
not rated yet Nov 02, 2011
F--k Hydrogen! Aluminium is way to go. Nice recyclable energy-holder. And you can spike aluminium with hydrogen too!

Very poignant. I fear you may have just swayed the opinions of everyone here...
kaasinees
1 / 5 (1) Nov 02, 2011
Waiting for lithium air batteries..
Manhar
3.7 / 5 (3) Nov 02, 2011
Gentlemen and Editors,
All of you are respected professional and your veiw points are viewed by acedemic professionals, students, researchers and industrial personnel. Please post your comments with valuable material and avoid using abusive words. We all will appreciate your coopration.
Thanks
holoman
not rated yet Nov 02, 2011
Hydrogen energy is slowly evolving with hydrogen service stations popping up in many parts of the world.

1. Hydrogen availability
2. Safe, high volume storage

Being the culprits for the use of the universes no. 1
element.

The first problem is becoming less so. The second has many
folks working on it and when the best solution is made we
will see the use of hydrogen go way up.
ShotmanMaslo
1 / 5 (3) Nov 04, 2011
Why not store hydrogen by binding it to carbon or nitrogen? (synthetic methanol, dimethylether or ammonia fuel).

http://energyfrom...ammonia/
Ricochet
not rated yet Nov 04, 2011
Why not store hydrogen by binding it to carbon or nitrogen? (synthetic methanol, dimethylether or ammonia fuel).

http://energyfrom...ammonia/


That would be way too simple. You must think in terms of elegance and penache.
3432682
1 / 5 (2) Nov 05, 2011
100 lb of this material could store 4.6 lb of hydrogen, about 237,000 btu, equivalent to just under 2 gallons of gasoline.
Grizzled
1 / 5 (1) Nov 07, 2011
3432682: And for the rest of us, non-US folks, could you translate the above into something sensible? How many lbs per gallon for instance? (P.S. That was just a bit of irony of course, I can convert the units myself if needs be. But... this is supposedly a scientific or engineering site, high time people learned to use metrics... Or are you waiting to lose another Martian lander to the confusion?)
Grizzled
1 / 5 (3) Nov 07, 2011
Why not store hydrogen by binding it to carbon or nitrogen? (synthetic methanol, dimethylether or ammonia


Why not store hydrogen by binding it to oxygen? Very convenient, safe in moderation, a little bit corrosive but that's ok.
Ricochet
not rated yet Nov 07, 2011
Why not store hydrogen by binding it to carbon or nitrogen? (synthetic methanol, dimethylether or ammonia


Why not store hydrogen by binding it to oxygen? Very convenient, safe in moderation, a little bit corrosive but that's ok.

I've tried that comment before... I think the gist of the answer was about the type of bond being too stable...
neiorah
not rated yet Nov 07, 2011
Binding to oxygen is called water..hee hee
ShotmanMaslo
3 / 5 (2) Nov 08, 2011
Why not store hydrogen by binding it to oxygen? Very convenient, safe in moderation, a little bit corrosive but that's ok.


Because that is called burning the hydrogen, and the resulting ash (water) has no chemical energy left, defeating the whole point.
rawa1
1 / 5 (1) Nov 08, 2011
We should solve the problems at their very beginning. The cold fusion will replace both the need of hydrogen economy, both the necessity of large batteries. Instead of this, the people are just seeking for any pretence of why not to solve the source of problem, i.e. the general lack of reliable energy source - they're just focusing to secondary problems, which actually don't exist. The hydrogen economy cannot solve the fossil fuel crisis, because most of hydrogen is produced from oil anyway. Therefore it's much cheaper to burn the oil directly in car engines, the conversion of oil into hydrogen is economical nonsense. We can even ask, why nuclear plants aren't producing hydrocarbons with reforming of carbon dioxide and water? The hydrocarbons are much more concentrated source of energy, than the hydrogen itself and they're more safe and easier to maintain. You can call it a carbon hydride technology, if you want.
ShotmanMaslo
1 / 5 (1) Nov 08, 2011
We can even ask, why nuclear plants aren't producing hydrocarbons with reforming of carbon dioxide and water.


They indeed could produce hydrocarbons or ammonia from air and water. They arent (in addition to anti-nuclear hysteria) because we dont need to, fossil fuels are still cheap.
rawa1
3 / 5 (2) Nov 08, 2011
BTW At the moment, when we use organic dye, i.e. carbon compound for storage of hydrogen, then the meaninglessness of the whole technology becomes even more apparent. We are essentially producing expensive and ineffective hydrocarbons (phtalocyanine dye) with using of pile of another hydrocarbons (i.e. oil fuel) just to store and transfer some hydrogen in form of chemical compound with carbon.
rawa1
1 / 5 (1) Nov 08, 2011
..because we dont need to, fossil fuels are still cheap..
The free market economy doesn't work well for fossil fuel. The price of sucking of oil from underground reservoir remains the very same, until this reservoir isn't suddenly depleted. What's worse, the companies mining oil tend to lie about actual state of oil supplies and they tend to exaggerate it, because they're motivated just with their own profit. The overestimation of oil supplies enables them to increase the quotas for oil extraction.

When countries will face the final end of fossil supplies, they will resort to war solution instead. Why Hitler attacked his ally, i.e. Soviet Union in 1941? Just he become nervous because of lack of oil. The war will require a lot of oil and it will increase the geopolitical nervousness even more. We are playing with fire, when we are ignoring the indicia of peak production.