A new system developed at the University of Michigan efficiently produces ethylene from harmful greenhouse gas CO2₂. This paves the way for a future of sustainable fuel production and cleaning our air.

What is known about the new invention

The ability to link carbon atoms into chains is a crucial step towards reusing CO₂ For the production of environmentally cleaner fuel. researchers developed an artificial photosynthesis systemBy bonding two carbon atoms together, this method can combine hydrocarbons with unprecedented efficiency, yield and durability, approximately five to six times better than other methods. Since ethylene is a hydrocarbon commonly used in plastic production, a direct application of the innovative system could be to capture carbon dioxide that would be released into the atmosphere for plastic production.

Ethylene is actually the most produced compound in the world. However, it is generally produced from oil and gas at high temperatures and pressures, resulting in the release of CO2.₂,
– write researchers.

The long-term goal is to create longer chains of carbon and hydrogen atoms to produce easily transportable liquid fuels. Part of the task is to remove all the oxygen from the CO molecule.₂ H to remove oxygen from a water molecule as well as to obtain carbon₂To get that hydrogen.

How does everything work?

• The device absorbs light through two types of semiconductors: a collection of gallium nitride nanowires, each just 50 nanometers (a few hundred atoms) wide, and the silicon substrate on which they are grown. The reaction of converting water and carbon dioxide into ethylene occurs on copper clusters containing about 30 atoms each covering the nanowires.
• The nanowires are immersed in water enriched with carbon dioxide and irradiated with light equivalent to sunlight. Light energy releases electrons that split water near the surface of gallium nitride nanowires. As a result, in addition to hydrogen participating in the ethylene reaction, oxygen is formed, which gallium nitride absorbs and turns into gallium nitride oxide.
• Copper binds well to hydrogen and captures carbon from carbon dioxide, converting it into carbon monoxide. The team believes that two carbon monoxide molecules came together with the hydrogen by the injection of energy from light and hydrogen in the mixture. The reaction is thought to be completed at the interface between copper and gallium nitride oxide, where two oxygen atoms split and three hydrogen atoms from the split water.

Competence

The team found that 61% of the free electrons produced by semiconductors with light contributed to the ethylene-forming reaction. Although another silver-copper-based catalyst achieved similar efficiency (about 50%), it operated in a carbon-based liquid and could only operate for a few hours before breaking down. Backwards, Michigan team’s device worked without slowing down for 116 hoursThe team operated similar devices for 3,000 hours.

The device produced four times more ethylene than the closest competing systems. In the future, scientists want to produce other multicomponent compounds, such as propanol with three carbon atoms or various liquid products. Fuel oils that can make many existing transportation technologies more reliable are the ultimate goal.

Unfortunately, the article does not fully explain how carbon dioxide is collected directly from the air or whether it should be connected to the capacities of factories emitting gas through the pipes of the installation. The second option will help prevent at least some of the new emissions, and if the first option, then we will be able to collect the existing emissions in the air, but the new ones will not go anywhere.