Discovery Files: Catching Rays

Using a common metal most famously found in self-cleaning ovens, Sossina Haile of CalTech University hopes to change our energy future. The metal is cerium[1] oxide -- or ceria -- and it is the centerpiece of a promising new technology developed by Haile and her colleagues that concentrates solar energy and uses it to efficiently convert carbon dioxide and water into fuels.

Credit: NSF/Karson Productions

Audio Transcript:

Capturing Sunbeams in a Jar?

I'm Bob Karson with the discovery files -- new advances in science and engineering from the National Science Foundation.

Solar energy, plentiful and free, but we need to find a practical way to bottle and store it. Scientists at Caltech have taken a unique approach to the challenge. A team has developed a solar reactor technology that uses the sun in a different way.

Their prototype reactor is two feet tall with a quartz window. The quartz acts as a magnifying glass to focus the sun's rays and a chamber that contains a material called ceria, a metal oxide. It has the ability to "inhale" oxygen into its crystalline structure.

When carbon dioxide or water is pumped into the reactor, the ceria strips the oxygen from it leaving behind carbon monoxide and/or hydrogen gas. The hydrogen gas could be used to fuel hydrogen fuel cells or, combined with the carbon monoxide and converted into liquid hydrocarbon fuels and once the ceria has inhaled all the oxygen it can, heating it up using sunlight makes it "exhale" the oxygen it took in starting the process anew.

We could someday have large-scale solar reactors that could actually take the CO2 emissions from coal-fired power plants and use sunlight to convert them to transportation fuels.

Nothing like, "catching some rays."

"The Discovery Files" covers projects funded by the government's National Science Foundation. Federally sponsored research -- brought to you, by you! Learn more at nsf.gov or on our podcast.
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Notes:

[1]cerium /'sɪrɪəm/
--The chemical element of atomic number 58, Ce (鈰). Cerium is a silver-white metal used in the production of glass and ceramics. (See it in Wikipedia.)