A palladium thin film has been used as part of new process to produce hydrogen with a purity of 99 per cent in a single device.

The new method involves shining ultraviolet light onto a single membrane made of layers of titanium dioxide and palladium.

A titanium dioxide nanotube array serves as a photocatalyst to generate the hydrogen, while the palladium acts as a purifier.

The study, carried out by Masashi Hattori, Kei Noda, and Kazumi Matsushige, from Kyoto University in Japan, was published in Applied Physics Letters recently.

"Alcohols are reformed photocatalytically and concurrently generated hydrogen is purified through the Pd [palladium]layer," the team said. "Hydrogen with a purity of more than 99 per cent was obtained from liquid alcohols under ultraviolet illumination onto the membrane."

Noda told PhysOrg.com: "The purification of the produced hydrogen gas was done with the Pd [palladium] layer.

"Only hydrogen can pass through the Pd layer and appear in the lower chamber. Other gases still exist inside the upper chamber."

It is hoped the breakthrough could be put to use in fuel cells by allowing them to be smaller and run on lower amounts of energy.

However, there is still a lot of work to be done to improve the process, the researchers say, with the amount of hydrogen produced still low.

They also claim that the palladium may need to be replaced with alloys of the metal to reduce "hydrogen embrittlement".

Source:

High-purity hydrogen generated from a single device (07/10/11)

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