Cool cat promises energy revolution

An inexpensive metal catalyst could be the key to generating hydrogen gas from water according to a team of researchers from Berkley Laboratory.

The team has discovered a molybdenum-oxo complex – PY5Me2 – that can catalyse the generation of hydrogen from neutral buffered water or sea water, without using additional acids or organic co-solvents.

“Our new proton reduction catalyst is based on a molybdenum-oxo metal complex that is about 70 times cheaper than platinum, today’s most widely used metal catalyst for splitting the water molecule,” said Hemamala Karunadasa, lead author of the paper.

Until now, platinum – a low valence precious metal – has been used in water-splitting reactions, at a cost of $2,000 an ounce.

“In addition, our catalyst does not require organic additives, and can operate in neutral water, even if it’s dirty, and can operate in sea water, the most abundant source of hydrogen on earth and a natural electrolyte,” Karunadasa said, “These qualities make our catalyst ideal for renewable energy and sustainable chemistry.”

The basic scientific challenge has been to create earth-abundant molecular systems that produce hydrogen from water with high catalytic activity and stability, Christopher Chang said, adding that the discovery establishes a new chemical paradigm for creating reduction catalysts that are highly active and robust in an aqueous medium.

Hydrogen gas could command a key role in future renewable energy technologies and can be combust or used in fuel cells to generate electricity. Its only emission is water vapour, and – if the electricity used to split the water is produced via wind or solar energy – is a completely environmentally clean and sustainable method of generating hydrogen.

The team will now focus on modifying the PY5Me ligand portion of the complex, and will investigate other metal complexes based on similar ligand platforms.