Scientists use liquid metal to convert carbon dioxide gas into solid "coal"

Many projects are currently experimenting with new ways to capture carbon from the point of emission. The gas is absorbed through metal-organic frameworks, porous powders, bubble-like membranes or materials made from clay or coffee grounds. But what to do with the captured carbon? After being extracted from these captured materials, the gas can then be reused to make concrete, carbonated drinks or fuel, or more of the gas can be stored underground. To store carbon dioxide, it is typically compressed into liquid form or combined with water and then injected deep underground. It reportedly interacted with basalt rock and solidified into carbonate minerals in just two years.

But other studies have found that this process may not be as effective as it seems. An MIT investigation found that only a thin top layer hardens - there's still a large pocket of gas underneath. This keeps it out of the atmosphere temporarily, but could leak in the future and release it all back into the air.

So the new research set out to solidify the carbon before it is solidified underground, so that it has no chance to "escape." The team consists of researchers from Australia, Germany, China and the United States.

The key to the new method is a liquid metal catalyst, composed of a gallium alloy and cerium. The research team first dissolved carbon dioxide in a beaker containing electrolyte, and then added a small amount of liquid metal catalyst. When an electric current is applied, the catalyst chemically activates the surface of the mixture, which slowly converts the carbon dioxide into solid carbon sheets.

The catalyst is designed to be an excellent conductor of electricity and carry out reactions efficiently. Because it's a liquid, the carbon sheets won't stick to it, which they tend to do if it's a solid catalyst. This allows it to run longer without scaling.

The researchers said that this process can be completed at room temperature, unlike other carbon conversion processes that require high temperatures, which consume large amounts of energy. The method can also be performed in a laboratory with relatively cheap and common equipment, and with a small power source.

“So far, carbon dioxide has only been transformed at extremely high temperatures.into a solid, making it industrially unfeasible," said Torben Daeneke, author of the study. "By using liquid metal as a catalyst, we have demonstrated that it is possible to convert the gas into carbon at room temperature in a single and scalable process. . Although more research is needed, this is a critical step toward providing solid storage of carbon. ”

Once the carbon solidifies, it can be safely stored underground indefinitely without fear of it leaking back into the atmosphere. But interestingly, this is not a possible outcome.

The technology has great potential to help remove greenhouse gases from the atmosphere, but as with any such research, more research is needed to determine how effective it can be on an industrial scale. , how effective it is from a logistical and economic perspective

　The study was published in the journal Nature Communications. : Scientists use liquid metal to convert carbon dioxide gas into solid "coal")