Chemists have figured out a new, more efficient way to create carbon based fuels from carbon dioxide (CO2). According to results, researchers identified a new additive that helps selectively convert CO2 into fuels containing multiple carbon atoms.
The results were quite shocking, says Jonas Peters, Bren Professor of Chemistry at Caltech. Usually, in these types of reactions with CO2, you see a lot of by-products like methane and hydrogen. In this case, the reaction is highly selective for more desirable fuels that contain multiple carbons, such as ethylene, ethanol, and propanol. We saw an 80 percent conversion to these multi-carbon fuel products, with only 20 percent going into hydrogen and methane.
Fuels with multiple carbon atoms more desirable because they tend to be liquid and liquid fuels store more energy per volume than gaseous ones. For instance, propanol liquid contains three carbon atoms, stores more energy than methane. The goal of chemists is to create artificially multi-carbon liquid transportation fuels using the available ingredients of sunlight, water, and CO2.
To find the ideal combination for making the multi-carbon fuels, the team experimented with a mix of different chemicals in the lab. They used an aqueous solution and a copper electrode, which served as both a catalyst and source of energy in place of the sun.
The group added CO2 to the solution, as well as a class of organic molecules called N-substituted arylpyridiniums. This film dramatically improved the fuel-making reaction, selectively producing the desirable chemicals ethanol, ethylene, and propanol.
It’s easy to make hydrogen under these conditions, says, Theodor Agapie, professor of chemistry at Caltech. But we want to discover the hydrogen production and favour high-energy density liquid fuels with carbon-carbon bonds.
The researchers also plan to test similar additives to see further improve the selectivity for the desired fuels. Ultimately, this information may help lead to alternate fuels made efficiently from sunlight, CO2, and water instead of oil.
More information: [Caltech Authors]