The Search for New Catalysts: at the Heart of Green Chemistry

Marc-André Légaré, who is finishing a Ph.D in chemistry at Université Laval, was one of the recipients of the Fonds de recherche du Québec’s Étudiants-chercheurs étoiles awards in October 2015. He received the award for an article published in the prestigious American publication Science regarding his research on metal-less catalysts. Complex molecular modelling computations are at the basis of his work and these need to be carried out on a supercomputer. Our compute server Colosse, located at Université Laval, provided the computing power Marc-André needed to get these results.

The Search for New Catalysts: at the Heart of Green Chemistry

Marc-André Légaré

Catalysts are used to produce numerous compounds used in various sectors such as the pharmaceutical industry, agriculture or materials science. « The use of catalysts — generally rare metals-based — makes it possible to activate useful chemical reactions that would otherwise be impossible », explains Marc-André. But there is a slight problem: the metals contained in most catalysts are not only rare and/or precious, they are often also toxic. « Due to the toxicity and scarcity of precious metals, alternative options to their use in catalysts are highly desirable. However, the unique properties of precious metals such a rhodium, platinum, palladium and iridium remain difficult to emulate with lighter and less toxic elements. For that reason, new concepts and new strategies have to be devised in order to be able to use greener

A Novel Approach

One type of reaction for which the use of a catalyst is necessary is the activation of the carbon-hydrogen (C-H) bond found in organic molécules. Marc-André and his colleagues decided to take a closer look at this type of reaction, but from a slightly different angle. « Our research is centered around a new strategy in catalytic organic synthesis: using two atoms (bore and nitrogen) in a single molecule to activate inert bonds. In fact, if you arrange these atoms correctly within the molecule, the combination of bore (electron poor) and nitrogen (electron rich) can imitate the reactivity of a metallic center. Our results demonstrate that the simultaneous action of bore and nitrogen makes it possible for the first time to catalyse the borylation of a C-H bond without using any metals. »

Advanced Research Computing: an Essential Tool

But how do you find the perfect combination of elements in the right configuration to replace the precious metals that were used in the past? Here is a hint: you do not try various combinations in the lab for years and miraculously stumble upon the right one the day before retirement. Nowadays, research in chemistry increasingly relies on advanced research computing, which helps researchers work a lot more efficiently. « Molecular modelization calculations are at the heart of our research. In order to design our new catalysts and predict their efficiency, we can optimize their structure and quantify their electronic properties by using quantum chemistry computation software. This predictive step not only makes us more efficient in the design of our catalysts, but it also gives us insights into the properties that actually make non-metal catalysts efficient. » In the last two years, Marc-André used over 16 core-years fo computing resources on our Colosse supercomputer. Had he used a single core running continuously, it would have taken him 16 years to complete the same amount of computations. At that speed, I wonder how many chemistry students would have the patience to complete a Ph.D…