Scientists Convert CO2 Into Solid Coal At Room Temperature

Scientists have harnessed metals in liquid form to convert carbon dioxide (CO2) into the solid coal by a technique that could make a breakthrough in capturing and storing carbon as well as offer a new pathway for removing all greenhouse gas from our atmosphere.

The research team from Australia-based RMIT University created a liquid-metal electrocatalyst which, at room temperature, transforms gaseous CO2 into carbon-containing solids.

And the catalyst also prevents coking in which the surface of the catalyst is stuck with solid carbon, an issue in the previous research in this field.

The answer lies in the phrase “room temperature”. Preparing carbon nanomaterials with other methods requires temperatures of up to hundreds of degrees C, meaning they are energy-intensive and not feasible for commercial use.

Similarly, compressing carbon dioxide into a liquid then injecting it underground is costly and harmful to the environment with leaking risks from storage sites, according to the researchers.

In addition, cutting CO2 to products with high values like fuel, and chemical feedstocks does not keep the carbon permanently. For example, the fuels release CO2 again once they're burnt.

Using liquid metal to convert CO2 into solid coal

Torben Daeneke, an RMIT researcher, said that turning the gas form into the solid form is probably a more sustainable way. He said:

Dorna Esrafilzadeh, an RMIT colleague of Daeneke, developed an electrochemical method to capture and turn atmospheric CO2 into solid carbon which can be stored.

Esrafilzadeh and colleagues designed a liquid metal catalyst whose surface properties increase its efficiency in conducting electricity and still chemically activate the surface.

The team dissolved carbon dioxide in a beaker, which they filled with an electrolyte liquid, along with a little liquid metal later charged with an electrical current.

And the carbon dioxide slowly changes to solid carbon flakes naturally separated from the surface of the liquid metal, which allows the continuous carbonaceous solid production.

Esrafilzdeh said that the produced carbon can also act as an electrode. She said:

Daeneke stated that there is still more work to be accomplished, but the early findings can be seen as “a crucial first step to delivering solid storage of carbon.”

The cooperation included many scientists from China, Australia, the U.S., and Germany. The research findings are now published in the Nature Communications journal.