Swiss
Almost every important chemical reaction, whether it is for industrial, medical or other applications, involves what is called a catalyst. Although these essential substances are not themselves consumed by the reaction, they can significantly change the rate at which the reaction occurs, or even make possible reactions that were previously impossible. However, these catalysts are often made of very precious or rare elements, and so researchers from Lausanne have been working on creating new catalysts out of more readily available materials.
that are cheaper, more readily available and that have a smaller environmental impact can be created. “One thing that we have created is a
nickel-based catalyst,” says Hu. “This catalyst is a very well defined compound; we know its
composition, we know its
structure, and we know how it reacts with other chemicals. This complex is very good at making carbon-carbon bonds, and this provides us with a way of making many different complex molecules, using what we call cross-coupling reactions.” “Our speciality is doing these cross-
coupling reactions on a group of chemicals called alkyl halides. These substrates have what are known as sp3 hybridised carbon fragments, and these are very difficult substrates
to carry out cross-coupling
reactions on due to a side reaction that is called beta-hydrogen elimination. What we have done is to create catalysts that are able to suppress this kind of hydrogen elimination, and we can use these catalysts for cross coupling reactions in many different reactions which were previously very difficult to achieve. We have carried out a lot of these reactions as examples of what can be done with our catalysts, and have created a fairly comprehensive list of the different ways that they can be used. The catalysts are now commercially available, and we have had orders from more than 30 companies who want to try them out.” As well as their research into making
Creating Catalysts
“In our laboratory we are interested in developing catalysts for two applications,” says Professor Xile Hu of the Laboratory of Inorganic Synthesis and Catalysis at the Ecole Polytechnique Fédérale de Lausanne (EPFL). “The first of these is related to the synthesis and preparation of
functional
molecules that can be used in medicines, materials and pharmaceuticals. The other application is related to energy storage, in that we are trying to develop catalysts that
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store energy from sunlight in the form of chemical fuels.” One of
the main priorities of the work
carried out by Hu and his colleagues is using what are known as earth-abundant elements when creating their catalysts. Many catalysts already exist for all kinds of reactions, but at present the majority of them are based upon precious metals such as platinum group metals. By focusing on using earth-abundant elements, catalysts
chemical synthesis more efficient, which utilises
both programme related to organic and inorganic
chemistry, Hu and his colleagues have another
energy
storage in the form of hydrogen. This side of their work involves electrochemistry and materials chemistry, and so the multidisciplinary aspect of their work is really highlighted by the difference in these two projects. “Solar energy is for obvious reasons an intermittent
source of energy. You can
capture energy from the sun during the day, but not by night,” explains Hu. “It is also very diffusive, meaning that the intensity for a given surface area is actually
Insight Publishers | Projects
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