If you remember anything from third grade science class, you know that photosynthesis is the process that allows plants to use solar energy to convert carbon dioxide (CO2) and water into sugars and other hydrocarbons. As an alternative to extracting fuel from biomass, some scientists have been looking to artificial photosynthesis technology to convert carbon dioxide gas into useful carbon-based chemicals–basically, taking carbon dioxide out of the atmosphere and putting it back into compounds we can use, like fuels.
The primary hurdle to making fuel from carbon dioxide has been the energy-intensive nature of the process. Using established methods, turning carbon dioxide into carbon monoxide is extremely inefficient because it requires more energy than can actually be stored in the fuel. But, University of Illinois chemical and biomolecular engineering professor Paul Kenis and his research group, along with researchers at the start-up company Dioxide Materials, have succeeded in overcoming this major obstacle to artificial photosynthesis.
In the journal Science, the Illinois group has documented their use of a novel ionic liquid to catalyze the reaction, greatly reducing the energy required to drive the process. The researchers then used an electrochemical cell to separate the gaseous carbon dioxide input and oxygen output from the liquid electrolyte catalyst. The cell design allowed the researchers to fine-tune the composition of the electrolyte stream to improve reaction kinetics, including adding ionic liquids as a co-catalyst.
“The key advantage [to artificial photosynthesis] is that there is no competition with the food supply,” said Masel, a co-principal investigator of the paper and CEO of Dioxide Materials, “and it is a lot cheaper to transmit electricity than it is to ship biomass to a refinery.”