Children visiting a science centre in East Oxford saw the world's first hydrogen-powered racing car - and met Mr Molecule.

The ground-breaking car, and the life-size carbon dioxide character, pictured, were two of the main attractions at Science Oxford, St Clement's, on Thursday.

Oxford is one of eight UK towns hosting the Royal Society of Chemistry's Fuelling the Future tour as part Chemistry Week 2007. Tom Baker, who donned the Mr Molecule costume, said: "This is the first time children have been able to meet carbon dioxide in person and hopefully it will help them to think more about ways to combat pollution."

The theme of the event was the motor sport industry and the role that chemical sciences must play in reducing carbon dioxide emissions.

As well as the racing car and a bio-ethanol fuelled Lotus Elise, an Audi A8 twin engine, provided by BP, was also on show.

The Audi display highlighted developments in clean fuel technology. A live video feed showed how the engines burned Ultimate fuel, producing less pollution.

It follows the launch of the RSC Fuelling the Future policy report, which recommended steps that must be made by government, industry and the public to cut carbon emissions from transport by 2020.

Dr Geraint Evans, of the National Non-Food Crops Centre, gave a talk on biofuels. Dr Evans said: "Biofuels will play a vital role in the development of sustainable energy sources and reducing carbon emissions, particularly in the short to medium-term.

"However, it must be highlighted that the overall contribution that biofuels can make is only a part in a much bigger picture.

"Significant investments must be made into alternative green technologies including improvements in energy efficiency in order to provide long-term solutions."