Molybdenum-oxo Complex to Split Water

Hydrogen gas, when used as a fuel, emits only water vapor as a product, making it potentially the 'cleanest' fuel around. Unfortunately, hydrogen gas has to produced and most of this comes from natural gas which is a fossil fuel. While the technique to produce hydrogen from natural gas is not expensive, it does add enormous quantities of carbon emissions to the atmosphere.

Hydrogen gas can be produced through the electrolysis of water, a cleaner and more sustainable method of producing hydrogen if the electricity required is generated via renewable technology such as solar or wind, but it requires a water-splitting catalyst.

Plants use enzymes, hydrogenases, during photosynthesis to split water, but these enzymes are highly unstable and de-activate when removed from their native environment.

Metal catalysts such as platinum are commercially available to split water, but these do tend to be expensive.

Scientists in the USA have found a molybdenum-oxo complex that acts as a catalyst for spiltting water without the use of additional acids or organic co-solvents. The new catalyst generates hydrogen from neutral buffered water or even sea water with a turnover frequency of ~2.4moles of hydrogen per mole of catalyst per second.

Hemamala I. Karunadasa, Christopher J. Chang, Jeffrey R. Long. A molecular molybdenum-oxo catalyst for generating hydrogen from water. Nature, 2010; 464 (7293): 1329 DOI: 10.1038/nature08969