Wisconsin Alumni Research Foundation

Clean Technology
Clean Technology
Visible-Range Sunlight Drives CO2 Reduction Process for Cheaper Syngas
WARF: P140115US01

Inventors: George Huber, Aniruddha Upadhye, Insoo Ro, Maria Isabel Tejedor-Anderson, Hyung Ju Kim

The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing a method for photocatalytically reducing CO2 to CO at unprecedented reaction rates.
In a reverse water gas shift reaction, CO2 is reduced to water and carbon monoxide (CO). The CO generated by this reaction is a key component in synthesis gas, also called syngas, which can be converted to liquid fuels using existing technologies.

This endothermic reaction must be driven by outside energy. The ability to harness sunlight reduces fossil energy inputs, improves overall efficiency and makes the process industrially relevant.
The Invention
UW–Madison researchers have developed a new method of reducing CO2 to CO via a reverse water gas shift reaction using visible solar light. The reaction produces a syngas mixture which can be further converted to liquid fuels.

In this process, CO2 (which can be obtained from many industrial processes) is contacted with a plasmonic catalyst in the presence of hydrogen. The catalyst is exposed to visible-range sunlight so that it undergoes an optical phenomenon called surface plasmon resonance, which causes metal electrons to oscillate in a certain way and accelerates the rate of CO2 reduction.

The process results in CO2 being reduced to water and CO that can be collected for downstream products.
  • Cost-effective production of syngas and other downstream products like formic acid and hydrocarbons
Key Benefits
  • Utilizes solar energy
  • Achieves light efficiency of at least four percent
  • Surface plasmon resonance in the catalyst increases rates of CO2 reduction by a factor of five or more.
  • Much more efficient than catalysts that only operate in the UV range
Stage of Development
The researchers have demonstrated improved solar efficiencies and accelerated reduction rates using an Au/TiO2 catalyst.
Additional Information
For More Information About the Inventors
For current licensing status, please contact Jennifer Gottwald at [javascript protected email address] or 608-960-9854