You may remember the concept of photosynthesis from biology or science lessons. The natural process by which plants and trees interact2 It is removed from the air and converted into glucose and oxygen with the help of sunlight (energy). Within limits Elkat A research team at the University of Antwerp, we are investigating, among other things, whether we, like trees, can absorb carbon dioxide2 It can be recycled using electrochemistry. By company2 By combining this with renewable energy and water, we have succeeded in recycling these harmful greenhouse gases into various valuable chemicals through an electrochemical reaction. For example, we can use carbon monoxide (CO), methane (CH).4), ethylene (C2H4) or formic acid (HCOOH).
In recent years, electrochemical reduction of carbon dioxide has been achieved2 Products of industrial value have become one of the most promising technologies for reducing carbon dioxide2 That humans emit (through burning fossil fuels, among other things) so-called anthropogenic carbon dioxide2emissions, can be reused. At the same time, it provides a way to store renewable energy from infrequently available sources, such as wind, solar and water.
My doctoral thesis focused on carbon dioxide recycling2 In formic acid. A chemical that could power your future laptop or smartphone via a “formic acid fuel cell,” but is also used as a preservative in foods, among other things. Next time, look for E236 on your food label.
Recycling company2 Unfortunately, it’s not that simple. Electrochemical reduction of carbon dioxide2 It requires a lot of energy and usually gives several products at the same time. Therefore, the catalyst plays a crucial role in this story.
Small nano factories
A catalyst is a component that speeds up a chemical reaction without being consumed during the reaction. In the electrochemical reduction of carbon dioxide2 This catalyst is usually metallic and is doubly important because it also determines the final product to be produced. For example, metals such as silver and gold produce primarily carbon monoxide, while metals such as bismuth, indium, or tin produce carbon dioxide2 Recycling into formic acid and carbon dioxide2 It can turn into methane, ethylene, etc.
You can view a catalyst as a huge collection of small “nano” factories, often 5 to 100 nanometers in size, where carbon dioxide is used2 Arrival of molecules and production of formic acid. Unfortunately, these nanofactories break down over time, releasing carbon dioxide2 The molecules can no longer be converted into formic acid. During my studies, I made several tin-based catalysts, tested them in an electrochemical reactor and investigated how and why they lose their activity over time.
The electrochemical reaction takes place on the surface of the catalyst, where carbon dioxide is present2Water and electricity together. To maximize this surface area while using as little metal as possible, most electrocatalysts are nanoparticles.
These nanoparticles, our ‘nano-factories’, are produced during carbon dioxide recycling2 Too heavily loaded and therefore will break in different ways. Then, nanoparticles can become loose, clump together, or just get crushed. Furthermore, they can also be “poisoned” by impurities in carbon dioxide2 The current will release tin dioxide (SnO2) Nanoparticles degrade over time to metallic tin (Sn), meaning they do not contain carbon dioxide2 more .
During my PhD studies, which I did in collaboration with the Flemish Institute for Technological Research (VITO) and with financial support from the Research Foundation – Flanders (FWO), I mapped this decline and tried to stop it using “nano” factories. To be protected by carbon shell. The microscopic images clearly show that the shape and structure are better preserved when the nanoparticles are covered with carbon.
Wipe with the tap open
Since the COVID-19 pandemic, you can find them almost everywhere, CO2 meter. This practical device helped us ventilate at the right time by indicating when carbon dioxide appears2The focus has become too high. Have you ever noticed that no matter how good the ventilation is, the concentration of carbon dioxide2 It never gets below 420 ppm? This is because this is the concentration of carbon dioxide2 In our Earth’s atmosphere.
Since the beginning of the Second Industrial Revolution at the end of the 19th century, there has been a rapid increase in anthropogenic carbon dioxide2Emissions and land use alter the natural greenhouse effect. More than 40 gigatonnes or 4000000000000 kg of carbon dioxide are currently produced annually.2 Emitted by human activities.
Although electrochemical reduction has not yet been applied industrially, scientists are beginning to use this technology to reduce carbon dioxide2 To test recycling on an increasingly larger scale. For example, within the ELCAT research group, we are working hard on an experimental setup to reduce CO22 It can be recycled on a larger scale into carbon monoxide (CO). Along with our other research on various aspects of electrochemical CO22 Reduction We are trying to overcome several important hurdles, so that this technology can be used in the (near) future to reduce CO22 Preventing and recycling emissions into products of industrial value.
If we want to limit global warming to 1.5 or 2 degrees Celsius, we not only need new technologies, such as electrochemical reduction of carbon dioxide.2To develop. We also need less carbon dioxide2 Emissions, otherwise this would be like wiping with a faucet open. At the recent Climate Summit (COP28) in Dubai, the landmark agreement took an important first step towards net zero CO22 emissions by 2050