Scientific results

Work of the CSAp (ICBMS) team led by Julien Leclaire

On The February 17, 2020

The LABEX iMUST chemistry chair obtained by Julien LECLAIRE has supported the launch of two themes: molecular recognition and assembly of polyelectrolytic species in water and the molecular and supramolecular chemistry of CO2.
In the framework of the first theme, the CSAp team was able to demonstrate that non-covalent self-aggregation phenomena not only affect the covalent equilibrium between macrocyclic species but are also not detected by classical chromatographic techniques, which leads the community to underestimate them[i]

In the second part, it was shown that the solutions resulting from CO2 capture by industrial amines are adaptive libraries of extractants for strategic metals. It was thus proved that CO2 capture can be used to recycle metals from end-of-life electric vehicle batteries, with an appreciable synergy between the two phenomena.

This latest work, published in the journal Nature Chemistry[ii] and widely covered by the media, has earned J. Leclaire le Prix Jean-Marie Lehn  of the Société Française de Chimie, have been selected by the American Chemical Society as one of the major events in chemistry in 2020 and have led to the creation of the Start up MeCaWaRe(Metal Capture for Waste Recycling) in December.   

[i] M. Dumartin, J. Septavaux, M. Donnier-Maréchal, E. Jeamet, E. Dumont, F. Perret, L. Vial, J. Leclaire, Chem. Sci. 2020, 11, 8151.

[ii] J. Septavaux, C. Tosi, P. Jame, C. Nervi, R. Gobetto, J. Leclaire, Nature Chem. 2020, 12, 202-212

Using carbon dioxide (CO2) to recover rare metals from your old phone? In other words, using a waste product to recycle other waste?
"This is the first use of CO2 for sustainable development purposes," stresses the Institute of Molecular and Supramolecular Chemistry and Biochemistry (ICBMS - University Lyon 1/CNRS/CPE/Insa Lyon), which is behind this innovation.

Excerpt from

The CO2 released into the atmosphere by combustion engines is one of the main factors in global warming. In Texas, it is re-injected into oil wells to improve their efficiency by making the most of their "extracting" capacities.

But in a more sustainable way, it can also be used to recover rare or precious metals contained in electronic waste, offering an alternative to their melting, which is costly in energy, or their solubilisation, which uses polluting products, according to researchers in Lyon.

One of them, Julien Leclaire, points out that industrialists have long known how to capture CO2 by making it absorbed by liquid solutions of amines, organic compounds, some of which exist in their natural state.

The molecules resulting from the combination of amines and CO2 are also capable of associating with various metals. For each amine, one or more compounds can be formed by combining with gas.

By modulating the quantity of CO2 and the solvent used, the metals dissolved in the liquid are deposited one after the other at the bottom of a container with a high level of purity.

"Our contribution is to have decoded this correspondence, to have determined which amine to use for which metal," explains Julien Leclaire.
"It's like in speed dating: what combination of qualities of both (amines and CO2) will make it possible to achieve the best marriage".

The method makes it possible to obtain very pure metals, even using "dirty" carbon dioxide.

Demonstration made immediately by Pr Leclaire, by connecting his installation... on the exhaust pipe of a car.

In his hand, a container containing a liquid. "We crushed a battery," he explains. "His metals have been turned into a solution with the help of acid - we're trying to find something else, something more environmentally friendly. The introduction of the amine gives rise to a purple colour. When CO2 is injected, the white precipitate" containing the metal appears.

"The fact that each metal is associated with a different partner gives it different properties and therefore makes it easier to separate them," says the researcher.

At the end of the operation, the CO2 can be reused or stored, an operation that is rarely performed to date because it is very expensive.

"What we are proposing is a brick in a process that generates added value and makes it possible to pay for the capture and burial of the CO2," notes Pr Leclaire.
"In this way, we are giving industry an economic incentive to look into CO2 capture," one of the possible solutions to prevent its dispersion into the atmosphere.