Translation. Region: Russian Federal
Source: State University Higher School of Economics – State University Higher School of Economics –
Researchers MIEM HSE Together with Chinese scientists, they created a catalyst that helps convert carbon dioxide into formic acid more efficiently. Thanks to the carbon coating, it works stably in an acidic environment and with a minimum amount of potassium, although it was previously believed that the element was necessary in high concentrations. This will reduce the cost of gas processing, and also simplify its industrial use – for example, in the production of fuel for environmentally friendly types of transport. Study published in the journal Nature Communications.
Electrochemical reduction of carbon dioxide is a process in which gas is converted into other chemical compounds under the influence of electric current. It has long been considered not only as a way to utilize CO₂, but also as a source of valuable raw materials. For example, formic acid, which can be used as a liquid fuel, solvent or component for the chemical industry.
However, the electrochemical reduction of CO₂ has a problem: a side reaction releases hydrogen, which reduces the efficiency of the process. In alkaline solutions, this problem is solved by adding more potassium ions (K⁺), but this not only makes the process more expensive, but also leads to the formation of sediments that clog the installation and impair its operation. And if, on the contrary, an acidic environment is used, the catalysts quickly deteriorate and lose their efficiency.
A group of researchers, including specialists from MIEM HSE, proposed an alternative approach. They developed a catalyst that works stably in an acidic environment with a minimum amount of potassium. Its base is indium oxide (In₂O₃), covered with a thin layer of carbon.
First, using computer modeling, MIEM employees found out how to control the distribution of ions on the catalyst surface. The model showed that the carbon coating not only protects the catalyst from destruction, but also forms an electric field that holds potassium ions near its surface. Thanks to this, potassium does not precipitate, and unwanted side reactions are suppressed.
To test the model’s predictions, Chinese scientists synthesized indium oxide nanoparticles and coated them with a thin layer of carbon. They then conducted a series of experiments in an electrolyte reactor. They used a highly acidic environment and several times less potassium than in traditional systems. Tests showed that even under such conditions, the catalyst remained stable: it remained active for more than 100 hours, while the efficiency of converting CO₂ into formic acid was 98.9%.
“We have managed to show that it is possible to abandon the excess potassium, which complicates the operation of the system. This approach made the process cheaper, and the catalyst itself more stable,” comments MIEM HSE Associate Professor Liu Dongyu.
To make sure that the carbon coating was indeed the culprit, the researchers conducted additional tests. They found that without the coating, indium oxide quickly reduced to metallic indium, which was much less effective at electrochemically reducing CO₂. This confirmed that it was the carbon layer that protected the catalyst, preventing it from deteriorating.
The method not only simplifies the technology of carbon dioxide processing, but also makes it more accessible for industrial use. Unlike traditional alkaline systems, it does not require a high concentration of potassium and eliminates the formation of sediments. The introduction of the technology into real installations can make carbon dioxide processing more environmentally friendly.
“We have made the process more stable and convenient for scaling, which means we have brought the electrochemical reduction of carbon dioxide closer to application in real production,” comments Andrey Vasenko, professor at MIEM HSE. “The technology can be useful not only for the synthesis of formic acid, but also for other processes related to the processing of CO₂.”
Please note: This information is raw content directly from the source of the information. It is exactly what the source states and does not reflect the position of MIL-OSI or its clients.