Very Green Energy

Rob Edwards in New Scientist:

IT IS the biggest contributor to climate change. Now chemists are hoping to convert carbon dioxide into a useful fuel, with a little help from the sun.

If they succeed, it will be possible to recycle the greenhouse gas produced by burning fossil fuels. The work could also lead to a way for future Mars missions to generate fuel for their return journey from carbon dioxide in the planet’s atmosphere.

Chemists have long hoped to find a method of bringing the combustion of fuel full circle by turning CO2 back into useful hydrocarbons. Now researchers at the University of Messina in Italy have developed an electro-catalytic technique they say could do the job. “The conversion of CO2 to fuel is not a dream, but an effective possibility which requires further research,” says team leader Gabriele Centi.

The researchers chemically reduced CO2 to produce eight and nine-carbon hydrocarbons using a catalyst of particles of platinum and palladium confined in carbon nanotubes. These hydrocarbons can be made into petrol and diesel.

To begin with, the researchers used sunlight plus a thin film of titanium dioxide to act as a photocatalyst to split water into oxygen gas plus protons and electrons. These are then carried off separately, via a proton membrane and wire respectively, before being combined with CO2 plus the nano-catalyst to produce the hydrocarbons.

More here.