December 2012

Two for the Price of One: Water and Carbon Dioxide Splitting via a Single Catalyst

A simple, robust catalyst is capable of both water oxidation and carbon dioxide splitting, two difficult yet key reactions for solar energy conversion.

Click to enlarge photo. Enlarge Photo

Image courtesy of UNC Chapel Hill (graphic art by Yan Liang)

Electrochemical cell for splitting carbon dioxide into carbon monoxide and oxygen.

The Science

Researchers have discovered a metal complex that catalyzes two important reactions, splitting water into hydrogen and oxygen (water oxidation) and reducing carbon dioxide to carbon monoxide (carbon dioxide reduction), in an electrochemical cell for splitting carbon dioxide into carbon monoxide and oxygen.

The Impact

The result provides an important first step towards finding a simple and effective method to use solar energy to drive difficult chemical reactions and generate high energy fuels, such as hydrogen or methanol.

Summary

In the field of artificial photosynthesis, solar fuels, generated by splitting water into hydrogen and oxygen or reducing carbon dioxide to carbon monoxide, methanol, or hydrocarbons, have great potential as alternative energy sources.  Such fuels could further solve an energy storage problem by allowing solar energy collected during the day to be stored and used at night.  A key challenge for solar fuel production is finding enough energy from sunlight to drive the complex water splitting oxidation and carbon dioxide reduction reactions. Researchers at the Solar Fuels EFRC at the University of North Carolina – Chapel Hill made an important discovery – a metal complex catalyst, a polypyridyl complex of ruthenium, catalyzed both water oxidation and carbon dioxide reduction. Using this catalyst, an electrochemical cell was developed that split carbon dioxide into carbon monoxide and oxygen.  As ruthenium is rare and expensive, a cheaper, more widely available alternative was needed; EFRC researchers discovered simple salts of copper (II), under the right conditions, react as robust electrocatalysts for oxidizing water. These results are an important step in developing a simple, highly effective approach for solar fuel production.

Contact

Thomas J. Meyer
UNC EFRC Director
University of North Carolina at Chapel Hill
tjmeyer@unc.edu

Catherine M. Heyer
UNC EFRC Assistant Director
University of North Carolina at Chapel Hill
cmheyer@unc.edu

Funding

DOE Office of Science, Basic Energy Sciences, Energy Frontier Research Centers (EFRC) program (authors JJC, MKB, PK, MRN, PGH and electrochemical studies by ZFC); Product analysis (by ZFC) was supported by the Army Research Office.

Publications

Zuofeng Chen, Javier J. Concepcion, M. Kyle Brennaman, Peng Kang, Michael R. Norris, Paul G. Hoertz, and Thomas J. Meyer. Splitting CO2 into CO and O2 by a Single Catalyst. Proc. Nat. Acad. Sci. U.S.A. 109(39), 15606 (2012). [DOI: 10.1073/pnas.1203122109External link]

Chen, Z. F., Meyer, T. J. "Copper(II) Catalysis of Water Oxidation" Angewandte Chemie International Edition, 52(2), 700 (2013). [DOI: 10.1002/anie.201207215External link]

Featured in: Quoi, C.Q., “A New Leaf: New Catalyst Boosts Artificial Photosynthesis as a Solar Alternative to Fossil Fuel.“ ScientificAmerican.com, June 13, 2012. http://www.scientificamerican.com/article.cfm?id=artificial-photosynthesis-fuel-alternativeExternal link

Related Links

Center for Solar Fuels EFRC

UNC EFRC HomepageExternal link

Highlight Categories

Program: BES, EFRCs

Performer/Facility: University

Additional: Collaborations, Non-DOE Interagency Collaboration

Last modified: 5/10/2013 11:21:36 AM