A research team led by RMIT University in Melbourne has developed a new technique, using a liquid metal electrolysis method, which they say efficiently converts carbon dioxide from a gas into solid particles of carbon, providing a the first step in a pathway towards removing CO2 from the atmosphere.

Current carbon capture techniques turn the gas into a liquid to be stored underground. The economic viability of doing this is questionable and it raises concerns about leaks from the storage site.

The new technique produces solid flakes of carbon, similar to coal, which are easier to store safely or used in a variety of applications including for battery electrodes.

The process uses a liquid metal catalyst with specific surface properties that make it extremely efficient at conducting electricity while chemically activating the surface.

The CO2 is dissolved in an electrolyte liquid along with a small amount of the liquid metal, which is then charged with an electrical current. The
CO2 slowly converts into solid flakes, which detach from the liquid metal surface, allowing for continuous production.

Previously, CO2 has only been converted into a solid at extremely high temperatures, making it industrially unviable.