The team designed a liquid metal which acts as a catalyst and quickly conducts electricity – which is used to capture the CO2 from the atmosphere – as well as boasting a special chemical coating that converts the gas. The carbon dioxide is then placed in a beaker filled with an electrolyte liquid and a small amount of the liquid metal. This then turns the CO2 into small, solid flakes of carbon which can eventually be compressed into coal, according to the research published in the journal Nature Communications.
Eventually, the goal will be to return the coal to the depths of the ground, essentially reversing carbon missions.
RMIT researcher Dr Torben Daeneke said: “While we can’t literally turn back time, turning carbon dioxide back into coal and burying it back in the ground is a bit like rewinding the emissions clock.
“To date, CO2 has only been converted into a solid at extremely high temperatures, making it industrially unviable.
“By using liquid metals as a catalyst, we’ve shown it’s possible to turn the gas back into carbon at room temperature, in a process that’s efficient and scalable.
“While more research needs to be done, it’s a crucial first step to delivering solid storage of carbon.”
Lead author, Dr Dorna Esrafilzadeh, a Vice-Chancellor’s Research Fellow in RMIT’s School of Engineering, added: “A side benefit of the process is that the carbon can hold electrical charge, becoming a supercapacitor, so it could potentially be used as a component in future vehicles.”
“The process also produces synthetic fuel as a by-product, which could also have industrial applications.”