Carbon dioxide is a huge problem due to its links to global warming and climate change.
Now a team of scientists have found a way to turn carbon dioxide into a viable energy source. A new study carried out by the U.S. Department of Energy’s Argonne National Laboratory and the University of Illinois at Chicago has revealed that sunlight can be used to make fuel from carbon dioxide, according to Nature World News.
Catalyst makes carbon dioxide more reactive
A press release written by the researchers says that carbon dioxide is a relatively unreactive chemical, and is therefore difficult to turn into other substances. One way to get around this is to find a catalyst, or a compound that would make carbon dioxide more likely to react.
Larry Curtiss, study author and chemist at Argonne, used tungsten diselenide. They made the catalyst into tiny flakes, increasing its surface area and encouraging reactions, allowing carbon dioxide to turn into carbon monoxide.
“Making fuel from carbon monoxide means travelling ‘downhill’ energetically, while trying to create it directly from carbon dioxide means needing to go ‘uphill,'” Peter Zapol, Argonne physicist, said in a statement.
Process results in carbon monoxide energy source
Carbon monoxide is also known as a greenhouse gas, but it is more reactive than carbon dioxide. Scientists also know how to use carbon monoxide as a fuel.
Plants use sunlight to make energy in a process called photosynthesis, and the same basic inputs are required to make carbon monoxide from carbon dioxide.
“In photosynthesis, trees need energy from light, water and carbon dioxide in order to make their fuel; in our experiment, the ingredients are the same, but the product is different,” Curtiss said.
In order to recreate the natural process, researchers made an “artificial leaf” capable of carrying out the necessary reactions.
Artificial leaf turns carbon dioxide into carbon monoxide
The first stage is to convert incoming photons into pairs of negatively-charged electrons and positively-charged “holes” which will then separate. Second these holes react with water to make protons and oxygen molecules. Lastly these protons, electrons and carbon dioxide react to make carbon monoxide and water.
“We burn so many different kinds of hydrocarbons — like coal, oil or gasoline — that finding an economical way to make chemical fuels more reusable with the help of sunlight might have a big impact,” Zapol said.
Another important point is the fact that little energy is lose during the reactions. “The less efficient a reaction is, the higher the energy cost to recycle carbon dioxide, so having an efficient reaction is crucial,” Zapol said.
Curtiss says that the tungsten diselenide catalyst lasts for over 100 hours. This is a tough test for catalysts to pass, and shows that it is quite durable.
You can read the full results of the study in the journal Science. The paper is titled “Nanostructured transition metal dichalcogenide electrocatalysts for CO2 reduction in ionic liquid.”
If the reaction can be used on a large scale it could help to reduce the impact of carbon dioxide emissions on our planet. Climate change is responsible for many events, including extreme weather, and the economic impact should not be underestimated.
Research into uses of carbon dioxide represents just one way that scientists are looking to slow the pace of climate change. There remains plenty of work to be done.