Turn CO2 into fuel

A catalyst capable of breaking chemical bonds in CO2 molecules will allow us to use carbon in the air as fuel in the same way as plants.

'Breaking down stable links in CO ₂ is one of the biggest challenges in synthetic chemistry', Frederic Goettmann, chemist at the Max Planck Institute for Glue and Frontier Research (Potsdam, Germany) , stated. 'But plants have done that for millions of years.'

Plants use solar energy to separate relatively stable chemical bonds between carbon atoms and oxygen in a CO ₂ molecule. In photosynthesis, the CO ₂ molecule is initially ' attached ' to nitrogen atoms, creating an unstable compound called carbamate. These compounds can be broken, allowing carbon to be used in the synthesis of other plant products, such as sugar and protein.

In an attempt to ' compete ' with natural photosynthesis, Goettmann and colleagues Arne Thomas, Markus Antonietti developed a catalyst derived from nitrogen to produce carbamates. They use flat layers of carbon and nitrogen atoms arranged in octagon to make this compound. On the outside, it looks like graphite.

(Photo: urgentclick.com) The team heated a mixture of CO ₂ and benzene with a catalyst at a temperature of 150 ºC and 3 times the pressure of air. First, the catalyst allows CO2 to form an unstable carbamate compound, like the carbamate in plants.

The catalyst allows benzene molecules to ' capture ' oxygen atoms from carbon dioxide molecules in carbamates, producing poorly stable phenol and CO.

"CO can be used to create new carbon-carbon bonds," Goettmann explains. 'We have taken the first steps in using CO from the air as an input fuel for chemical synthesis'.

Future refining technology can help chemists no longer have to rely too much on fossil fuels in creating chemical products. Liquid fuel can also be made from CO, which CO can be extracted from CO ₂ , Goettmann said. 'In the Second World War, Germany used CO from coal to produce fuel. In the 1980s, South Africa did the same thing. '

Researchers are seeking to bring their approach closer to the synthesis of plants."Benzene's reaction provides the energy to separate CO ₂ ," Goettmann said. 'But in plants it is light'. The new catalyst absorbs ultraviolet radiation, so the team is conducting tests to see if light can provide that energy.

Joe Wood, a chemical engineer at Birmingham University (UK), also studied how to freeze CO ₂ . ' More and more people are interested in using CO2 as an input in the chemical industry,' he said.

The Max Planck Institute's technology has only been proven on a small scale and its performance is quite low - about 20%, Joe said.'But it seems very promising,' he added: 'The catalyst can be created at a low cost and operates at relatively low temperatures'.

The products of this technique are very suitable for making pharmaceuticals or pesticides

Viet Linh