A more efficient way to convert Greenhouse Gases (GHGs) into green fuel

A more efficient way to convert Greenhouse Gases (GHGs) into green fuel

In new research, researchers at the University of Chicago were able to find a way to control water molecules, so that it can help increase the efficiency of the electrochemical reduction of carbon dioxide (CO2R). This is to create a closed circuit of clean energy. This new method enabled the team to carry out the aforementioned reduction process with an efficiency of up to 100% under moderately acidic conditions, and using gold or zinc to catalyze the reaction.

Carbon dioxide – as we know – is the most prominent greenhouse gas, and is responsible alone for up to 78% of the change in the energy balance in the atmosphere between 1990 and 2022; This is due to the fact that it is a by-product of the combustion of fossil fuels, this fuel that has represented the backbone of industry and growth for humanity for more than a century, and still is!

Carbon dioxide enters the atmosphere through automobile exhaust, coal-fired power plants, as well as emissions from heavy industries such as iron, steel, and cement. Some renewable energy resources even produce small amounts of carbon dioxide.

Rearrangement of atomsCO2

When looking at the molecular structure of carbon dioxide, we find that it consists of two oxygen atoms and a carbon atom, as these atoms are connected to each other through two double covalent bonds. However, this molecular structure can be reorganized through a process known as electrochemical reduction of carbon dioxide, or “CO2R”, so that this harmful molecule in the atmosphere can be converted into clean fuel or materials. Useful chemistry. However, this process has a serious flaw, which is that it is difficult to control. Which sometimes leads to obtaining unwanted secondary compounds.

The main products of the electrochemical reduction of carbon dioxide include compounds such as methane,ethylene, and ethanol. These are very important compounds for many applications, and this process can represent an environmentally friendly solution. To recycle emissions, achieve a circular economy, and reduce dependence on fossil fuels.

In a research paper published weeks ago in the journal Nature Catalysis, researchers from the laboratory of Professor Amanchukwu at the University of Chicago School of Molecular Engineering identified a way to control water molecules, so that the process of electrochemical reduction of carbon dioxide can be made more efficient. Through their new method, the researchers were able to conduct CO2R with an unprecedented efficiency of nearly 100%.

Doctoral researcher Reggie Gomez, the first author of the new research paper, said: “Imagine with me that humanity reaches a stage where it can obtain clean electricity through renewable sources such as solar and wind energy, and then use this green electricity in the work of reducing carbon dioxide, and converting it into fuel again; Only then can we say: We have reached a closed circle of clean energy.”

Problem and solution

To bring the matter closer to the readers of Earth Guards, the disintegration of the molecules of any chemical compound is a process similar to the first shot in a game of billiards, where the balls (atoms) are scattered randomly across the table, and sometimes the balls settle in places that the player did not want them to be.

Similarly, researchers use water and electricity to break down carbon dioxide molecules and rearrange them. However, this process also allows the carbon and oxygen atoms resulting from the breakdown of CO2 to mix with the hydrogen atoms present in the water. Because of this, stable pairs of hydrogen atoms are often formed, a process called the hydrogen production reaction (HER), which makes the CO2R reaction less efficient; To deplete the hydrogen production process of energy and atoms, which researchers were trying to exploit to form other compounds.

This phenomenon – unfortunately – exists even with the use of small amounts of water, which has undermined reliance on the CO2R process as a sustainable solution to get rid of carbon dioxide. So the laboratory of Professor Amanchukwu, who is famous for his research in the field of batteries, applied some concepts derived from aqueous batteries to solve this problem, assuming that controlling water – using organic solvents – could provide a solution.

To understand the solution more clearly, we must know that both the CO2R and HER processes depend on water as a donor of protons, but – by using organic solvents and acidic additives – the research team was able to control in some way the behavior of the water, by finding the ideal balance that allows the water to donate only the appropriate amount of protons that allow the formation of the desired compounds, instead of producing hydrogen gas. And other unwanted substances such as carbonates.

The problem is due to the fact that water is a compound made from the union of a hydroxide group (OH) with a hydrogen atom. As we know from general chemistry, carbon dioxide reacts with hydroxide to form carbonates, which is an undesirable result, and it also undermines the production process of other compounds. In addition to this, the traditional CO2R process relies on the use of precious metals as catalysts, such as gold, silver, and platinum. Because they are very stable elements, they also prevent the HER process, but this is impossible to apply on an industrial level. Because of the high cost.

The new method overcomes the previous two problems, as the required results can be obtained by controlling the behavior of water (electrolyte), and cheap catalysts can be used that can work at room temperature, such as zinc, which is one of the most abundant elements on Earth. Which means that converting the process of electrochemical reduction of carbon dioxide may become possible on an industrial scale, and this will contribute – significantly – to reducing climate change, in addition to supporting efforts to achieve the goals ofsustainable development.