Photocatalytic CO₂ Reduction

Artificial Photosynthesis

There can be little doubt that CO2 currently has the highest public profile of any molecule

• Annual anthropogenic CO₂ emissions – 24 billion metric ton
  − Global chemical industry use - 115 metric tons
  − CO₂ capture and sequestration is necessary
• Potentially, however, there are better ways to deal with CO₂.

Artificial Photosynthesis - an extremely attractive scenario would be to efficiently produce large quantities of methanol or hydrocarbon fuels directly from captured CO₂

The best known catalysts are TiO₂ based but suffer from limited absorption of solar spectrum (UV only), lack of selectivity, and low efficiency. We are employing catalyst by design approach to find a catalyst that can absorb visible light and reduce CO₂ selectively and efficiently. We have recently shown that GaN-ZnO₂ catalyst which absorbs visible light can selectively reduce CO₂ to CO. This catalyst is not very efficient and we are examining a variety of catalyst by density functional theoretical studies to select the ones that can potentially reduce CO₂ more efficiently.

The financial assistance for this research was provided under a laboratory directed research program and is gratefully acknowledged.

The principal technical contact for this project is Dr. Chaitanya K. Narula, tel. (865) 574-8445, e-mail narulack@ornl.gov.