New metal hydride clusters provide insights into hydrogen storage

Sep 22, 2011

A study published by researchers at the RIKEN Advanced Science Institute (ASI) has shed first-ever light on a class of heterometallic molecular structures whose unique features point the way to breakthroughs in the development of lightweight fuel cell technology. The structures contain a previously-unexplored combination of rare-earth and d-transition metals ideally suited to the compact storage of hydrogen.

The most abundant element in the universe, hydrogen holds great promise as a source of clean, renewable energy, producing nothing but water as a byproduct and thus avoiding the environmental dangers associated with existing mainstream energy sources. Broad adoption of hydrogen, however, has stalled because in its natural gaseous state, the element simply takes up too much space to store and transport efficiently.

One way to solve this problem is to use metal hydrides, metallic compounds that incorporate , as a storage medium for hydrogen. In this technique, the metal hydrides bind to hydrogen to produce a solid one thousand times or more smaller than the original . The hydrogen can then later be released from the solid by heating it to a given temperature.

The new heterometallic hydride clusters synthesized by the RIKEN researchers use rare-earth and d-transition metals as building blocks and exploit the advantages of both. Rare earth metal hydrides remove one major obstacle by enabling analysis using X-ray diffraction, a technique which is infeasible for most other metal hydrides - offering unique insights into underlying reaction processes involved. Rare earth metal hydrides on their own, however, do not undergo reversible hydrogen addition and release, the cornerstone of hydrogen storage. This becomes possible through the addition of a d-transition metal, in this case tungsten (W) or molybdenum (Mo).

While rare-earth / d-transition metal-type metallic hydride complexes have been studied in the past, the current research is the first to explore complexes with multiple rare earth atoms of the form Ln4MHn and with well-defined structures (Ln = a rare-earth metal such as yttrium, M = a d-transition metal, either tungsten or molybdenum, and H = hydrogen). In a paper in Nature Chemistry, the researchers show that these complexes exhibit unique reactivity properties, pointing the way to new techniques and promising environmentally-friendly solutions to today's pressing energy needs.

Explore further: Researchers create materials that reproduce cephalopods' ability to quickly change colors and textures

add to favorites email to friend print save as pdf

Related Stories

Hydrogen storage in nanoparticles works

Mar 31, 2008

Dutch chemist Kees Baldé has demonstrated that hydrogen can be efficiently stored in nanoparticles. This allows hydrogen storage to be more easily used in mobile applications. Baldé discovered that 30 nanometre particles ...

On the way to hydrogen storage?

Apr 19, 2011

(PhysOrg.com) -- The car of the future could be propelled by a fuel cell powered with hydrogen. But what will the fuel tank look like? Hydrogen gas is not only explosive but also very space-consuming. Storage ...

Putting the squeeze on rare earth metals

Apr 15, 2011

(PhysOrg.com) -- Rare-earth metals are a series of elements that represent one of the final frontiers of chemical exploration. The vigorous reactivity of these substances, however, has made it difficult for ...

Recommended for you

Separation of para and ortho water

5 hours ago

(Phys.org) —Not all water is equal—at least not at the molecular level. There are two versions of the water molecule, para and ortho water, in which the spin states of the hydrogen nuclei are different. ...

User comments : 0