In search of a more sustainable chemistry.
Text: Yvonne Vahlensieck
Catalysts speed up chemical reactions and are essential for industry; but there is still some room for improvement. Murielle Delley wants to make catalysts more efficient and more sustainable.
Even as a child, Murielle Delley was always curious about how things worked. This spirit of discovery led her to study chemistry at ETH Zurich and to carry out research into catalytic processes. Without catalysts, the world would be a different place. For example, there would be barely any nitrogen fertilizers for agriculture, and the world’s population would have long since been unable to feed itself.
Catalysts are also indispensable for the production of many medicines. “Without catalysts, many chemical processes simply wouldn’t happen at appreciable rates in the first place, or you’d have to put a huge amount of energy into them,” says Delley, who is now an assistant professor in the Department of Chemistry at the University of Basel.
Catalysts are used in 80 percent of all chemical products. Although they are highly effective, there is still considerable room for improvement. This is where Delley and her research come in — she wants to develop catalysts that are more effective and better for the environment. This groundbreaking work, which takes chemistry along the path to greater sustainability, has already earned her numerous grants, scholarships and awards.
Moving away from the rare elements
“Today’s catalysts still have a number of disadvantages,” says Delley. For one thing, they are often insufficiently selective for a particular reaction — which means they produce a lot of unwanted waste materials and the end product must undergo an additional purification step. Moreover, even with the aid of a catalyst, many chemical processes still need a large influx of energy, usually in the form of heat.
Another issue is that many catalysts consist of precious metals such as platinum, which are a limited resource. With that in mind, Delley has begun to take a closer look at another group of materials, known as transition metal phosphides and transition metal sulfides. Along with either phosphorus or sulfur, these materials contain elements that are abundant on Earth, such as iron. “They are particularly interesting to us because they have certain catalytic properties that are similar to those of precious metals,” says Delley.
Targeted search instead of trial and error
Delley’s team investigates the catalytic processes that occur on the surfaces of transition metal phosphides and transition metal sulfides. It’s no easy task: “On the surface of these materials, there are many reactions going on at different sites at the same time,” she says. These processes are still not fully understood today — and that’s precisely what fascinates her about them: “There’s still so much to discover.” In order to decipher the enigma of these complex processes, she turns to a variety of techniques, including various kinds of microscopy and spectroscopy. Other ideas come from biological systems, as these also involve catalytic processes. Delley uses innovative methods to try and imitate the tricks of nature on the surface of her catalysts, such as applying an electric field.
Until now, the development of new catalysts has often relied on empirical research, in which scientists would simply try out a series of substances and use the ones that worked best. “A lot has been achieved that way, but it would be even better to move forward in a targeted manner,” explains Delley. “If we know exactly what’s happening on the surface, then we may be able to design a catalyst with exactly the properties we want.” Ideally, this would accelerate product development, reduce waste products and save energy while eliminating the need for rare precious metals. As an assistant professor, Delley now rarely has the opportunity to conduct experiments herself. “But I supply ideas, discuss the results and plan the next steps with my team. That way, I can continue to pursue my core interest in research.” She has therefore fulfilled her childhood dream: finding out how something works for herself.
Murielle Delley was born in Schlieren, Zurich, in 1989 and studied chemistry at ETH Zurich. In 2019, she received the ETH Medal and the Prix Schläfli for her doctoral thesis. Following a research fellowship at Yale University in the United States, she moved to the University of Basel, where she has led her own research group since 2020. In 2023, she became a tenure-track assistant professor of inorganic chemistry. Last year, the 35-year-old Swiss scientist received the Ruzicka Prize, which recognizes outstanding young researchers in chemistry. She lives with her husband and two children in Bottmingen, Basel-Landschaft.
More articles in this issue of UNI NOVA (November 2025).