New technique generating hydrogen gas from water

New technique for generating hydrogen gas from water

1:03 AM, 10th February 2012
New technique for generating hydrogen gas from water
Using a molybdenite complex and the PY5Me2 ligand, researchers synthesized a molecule that mimics catalytically active triangular molybdenum disulfide edge-sites. The result is an entire layer of catalytically active material. Molybdenum atoms are shown as green, sulfur as yellow.

CALIFORNIA, US: A technique for creating a new molecule that structurally and chemically replicates the active part of the widely used industrial catalyst molybdenite has been developed by researchers with the US Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). This technique holds promise for the creation of catalytic materials that can serve as effective low-cost alternatives to platinum for generating hydrogen gas from water that is acidic.

Christopher Chang, Chemist, Berkeley Lab and the University of California (UC) Berkeley and Jeffrey Long, Chemist, Berkeley Lab and the University of California (UC) Berkeley,led a research team that synthesized a molecule to mimic the triangle-shaped molybdenum disulfide units along the edges of molybdenite crystals, which is where almost all of the catalytic activity takes place. Since the bulk of molybdenite crystalline material is relatively inert from a catalytic standpoint, molecular analogs of the catalytically active edge sites could be used to make new materials that are much more efficient and cost-effective catalysts.

“Using molecular chemistry, we’ve been able to capture the functional essence of molybdenite and synthesize the smallest possible unit of its proposed catalytic active site. It should now be possible to design new catalysts that have a high density of active sites so we get the same catalytic activity with much less material,” said Chang.

“Inorganic solids, such as molybdenite, are an important class of catalysts that often derive their activity from sparse active edge sites, which are structurally distinct from the inactive bulk of the molecular solid,” said Long. Currently, the best available technique for producing hydrogen is to split water molecules into molecules of hydrogen and oxygen using platinum as the catalyst. However, with platinum going for more than $2,000 an ounce, the market is wide open for a low cost alternative catalyst. Molybdenite is far more plentiful and about 1/70th the cost of platinum, but poses other problems.

Chang, Long and their research team met this challenge using a pentapyridyl ligand known as PY5Me2 to create a molybdenum disulfide molecule that, while not found in nature, is stable and structurally identical to the proposed triangular edge sites of molybdenite. It was shown that these synthesized molecules can form a layer of material that is analogous to constructing a sulfide edge of molybdenite. “The electronic structure of our molecular analog can be adjusted through ligand modifications. This suggests we should be able to tailor the material’s activity, stability and required over-potential for proton reduction to improve its performance,” said Long.

“We’re now looking to develop molecular analogs of active sites in other catalytic materials that will work over a range of pH conditions, as well as extend this work to photocatalytic systems,” said Chang. “Our molecular analog for the molybdenite active site might not be a replacement for any existing catalytic materials but it does provide a way to increase the density of active sites in inorganic solid catalytic materials and thereby allow us to do more with less,” said Long.

© Berkeley laboratory News

0 Comments

Login

Your Comments (Up to 2000 characters)
Please respect our community and the integrity of its participants. WOC reserves the right to moderate and approve your comment.

Related News


Bioplastics demand to reach $2.9 billion by 2015

ROCKVILLE, US: The global demand for biodegradable and bio-based plastics will more than triple to over one million metric tonne in 2015, valued at $2 ...

Read more
Fluor to provide project management services to Syncrude Canada

IRVING, US: Fluor Corporation announced that it will provide project management services for the Mildred Lake Mine Replacement (MLMR) project for Sy ...

Read more
Development of soap with magnetic properties

BRISTOL, UK: Scientists from the University of Bristol have developed soap, composed of iron rich salts dissolved in water that responds to a magnetic ...

Read more
SOHM launches additional dermatology products in India

BUENA PARK, US: SOHM Inc, a generic pharmaceuticals, nutraceutical and dermatology company, announced its launch of additional dermatology products in ...

Read more
Clariant opens new crop protection laboratory in Thane

MUMBAI, INDIA: Clariant announced the opening of a new crop protection laboratory by its Industrial & Consumer Specialties (ICS) business unit in ...

Read more
Indian firm to set up plant to turn plastic waste into fuel

MUMBAI, INDIA: Sustainable Technologies & Environmental Projects (STEPS), plans to set up a plant to convert plastic waste into light diesel, calo ...

Read more