27 november 2012

Route to a 'long-life' mobile fuel cell

Science | Technology

People showing their modern mobile phones

A new catalyst developed by a team led by Oxford University scientists could be the key to creating small, long-lasting fuel cells for powering mobile devices.

The catalyst can directly convert methanol into hydrogen at the relatively low temperature of 150 degrees Celsius and, crucially, generates no detectable amount of carbon monoxide (CO) – a poison that damages fuel cells and gives them a short lifespan.

The research, reported in this week's Nature Communications, demonstrates how a catalyst made of copper nanoparticles trapped in zinc gallium oxide can produce CO-free hydrogen which could be fed directly into a proton exchange membrane (PEM) fuel cell. Such a system could be ideal for generating 'energy on the go' to power devices such as mobile phones, MP3 players, and laptops, where both space and heat management are an issue.

'There has been a huge effort to identify a promising catalyst for this reaction to supply high quality hydrogen for vehicle fuel cells but the demand for power from a vehicle is high, over 100KW, and so far these efforts have been unsuccessful,' said Professor Edman Tsang of Oxford University's Department of Chemistry, lead author of the report.

'What we have found is that although the activity of our catalyst is still very low for vehicle applications it is sufficient to power up small fuel cells for mobile devices that only need from 0.5 to 100W. It can produce hydrogen gas for such fuel cells without the problem of also producing carbon monoxide, which is poisonous to fuel cells systems.'

It is thought to be the first time a process has been shown to generate useful amounts of CO-free hydrogen at such a low temperature.

The research was carried out by an international team including scientists from Oxford's Department of Chemistry and the Department of Materials. The work was funded by the Engineering and Physical Sciences Research Council (EPSRC). Isis Innovation, the University's technology transfer company, is marketing the technology.

A report of the research, entitled 'Non-syn gas direct steam reforming of methanol to hydrogen and carbon dioxide at low temperature', is published in Nature Communications.

Image: people holding mobile devices: from Shutterstock.