New material captures and converts carbon into useful chemicals

University of California Berkeley (UC Berkeley) chemists have taken a promising new material that captures and stores carbon dioxide and alters it to convert the captured carbon into a chemical useful to industry.
Sponge-like materials called covalent organic frameworks (COFs) can soak up carbon dioxide, making them useful in removing the potent greenhouse gas from power plant emissions or directly from the air.

Chemists Christopher Chang and Omar Yaghi, who invented COFs, added a metal catalyst to the crystal structure in order to turn the captured carbon dioxide into carbon monoxide, a primary building block for a wide range of chemical products, including fuels, pharmaceuticals and plastics.

''To date, such porous materials have mainly been used for carbon capture and separation, but in showing they can also be used for carbon dioxide catalysis, our results open up a huge range of potential applications in catalysis and energy,'' said Chang, the Class of 1942 Chair in chemistry and a chemist with Berkeley Lab's Chemical Sciences Division.

Chang and Yaghi, the James and Neeltje Tretter Professor of Chemistry, published their findings in the Aug. 28 issue of the journal Science.

In 2005, Yaghi and his research group at the University of Michigan designed and developed the first COFs as a means of separating carbon dioxide from flue gases.

A COF is a porous three-dimensional crystal consisting of a tightly folded, compact framework that has an extraordinarily large internal surface area.

A COF the size of a sugar cube, were it to be opened and unfolded, would blanket a football field. The sponge-like quality of a COF's vast internal surface area enables the system to absorb and store enormous quantities of targeted molecules, such as carbon dioxide.

Adding a catalyst, in this case cobalt metal atoms, converted the storage material into an active structure that can turn out useful products.

Chang is also a Howard Hughes Medical Institute investigator at UC Berkeley and a professor of molecular and cell biology. Yaghi is also a chemist at Berkeley Lab and co-director of the Kavli Energy NanoScience Institute (Kavli-ENSI) at UC Berkeley.