[peppercorn (OP)]

Obviously, additional energy would be required (heating), but do such materials exist?

I know the opposite process can be found in a car's catalytic converter.

[Evie]

Here's an article talking about this new process:

http://www.sciencedaily.com/releases/2007/04/070418091932.htm

The device designed by Kubiak and Sathrum to split carbon dioxide utilizes a semiconductor and two thin layers of catalysts.  It splits carbon dioxide to generate carbon monoxide and oxygen in a three-step process.  The first step is the capture of solar energy photons by the semiconductor.  The second step is the conversion of optical energy into electrical energy by the semiconductor.  The third step is the deployment of electrical energy to the catalysts.  The catalysts convert carbon dioxide to carbon monoxide on one side of the device and to oxygen on the other side.

Because electrons are passed around in these reactions, a special type of catalyst that can convert electrical energy to chemical energy is required  Researchers in Kubiak’s laboratory have created a large molecule with three nickel atoms at its heart that has proven to be an effective catalyst for this process.

[Bored chemist]

Catalysts increase the speed of a reaction in both directions. If a converter will catalyse the reaction 2CO +O2--> 2CO2 then it will also speed up the reverse reaction, and to exactly the same extent.

[peppercorn (OP)]

Evie,

Thanks for your link. Sounds like an interesting process.
Some time ago I came across a similar 'device' for solar-to-hydrogen:

http://www.sandia.gov/news-center/news-releases/2005/renew-energy-batt/nano.html

Both these processes appear to have the simplicity to make a big difference in making solar energy more usable.

[peppercorn (OP)]

BC,

Hadn't realised that catalysts were bi-directional. I sort of assumed they had a build-in 'handedness'.

This sparks the question, if CO & CO2 are found in a gas stream (like car exhaust) what pushes the catalyst towards the forming CO2 & not CO?