Welcome to Essyllt Louarn: Meet Our New Conference Lecturer

Recently appointed as a conference lecturer at Ircelyon, Essyllt Louarn brings her expertise in mass spectrometry to the laboratory’s teams. With an unconventional academic background, diverse scientific projects, and a passion for Breton culture, she traces molecules—from the ocean to testing benches.

Could you briefly introduce your academic and professional background before joining Ircelyon?

I first completed a PhD in chemical oceanography at the University of Western Brittany in Brest. I analyzed fluorinated greenhouse gases in the ocean to trace water masses. I then became a lecturer at the University of Paris-Sud (now Paris-Saclay). There, I worked on the analysis of chlorofluorocarbons (CFC) and hydrofluorocarbons (HFC) in water within a lab specializing in mass spectrometry. I developed methods to analyze these compounds, then volatile organic compounds (VOC), using a very specific mass spectrometer—one we built in the lab itself!
Years later, I decided to move to Lyon, and Ircelyon welcomed me as my host lab within the CARE team. My first project involved analyzing unregulated volatile organic compounds emitted by vehicles on the PIREP test bench. This bench stems from the research projects “Innovating Process for the Reduction of Particulate Emissions” PIREP (2010–2012) and PIREP2, funded by ADEME and ANR, with Philippe Vernoux as coordinator.
I arrived during the Covid pandemic, which was not ideal for lab work, but I was relieved from teaching duties, leaving me time for research. Later, I was recharged with teaching responsibilities, so I alternated between Orsay to teach and Lyon for my research for years. It was during this period that I submitted, alongside Mathieu Prévot, the ANR project MEGOPE (mass spectrometry for green production of organic compounds by electrocatalysis), focused on real-time analysis of electrochemical systems via mass spectrometry. This project is nearing completion, with Clément Spadetto’s thesis defense taking place at the end of September.

What project(s) or research theme(s) will you work on at the laboratory? What do they entail?

My specialty is mass spectrometry applied to chemical analysis (volatile organic compounds, halogenated compounds, etc.). What’s exciting about this is the direct analysis of samples. I’ve worked extensively on pollution remediation, collaborating on plasma processes, photocatalysis, and catalysis, especially with Sonia Gil. The goal is to observe what forms during these processes to identify byproducts. To do this, I develop analytical methods based on mass spectrometry to better understand these phenomena.

What collaborations would you like to develop within Ircelyon and beyond?

I’m completely new to the world of catalysis, so everything is a discovery! There were so many aspects I was unaware of, and this Ircelyon-specific world is fascinating. I’ll take the time to talk to colleagues internally to explore these new topics. It’s a fresh area for me: helping better understand the chemical systems involved.
First, I’ll continue collaborating with Mathieu Prévot: Clément Spadetto’s thesis opened many avenues, and a new topic is emerging in collaboration with external colleagues.
I also exchange ideas with colleagues from CPE Lyon and at Ircelyon, discussing analyses we could implement.
I maintain a presence at Saclay, where colleagues want to work on PFAS depollution and the resulting byproducts. Indeed, a PFAS research studio is being set up within the Planetary Challenges, Territories, and Transitions Institute (“défis planétaires, territoires et transitions” or DPTT) on a Lyon-Saint-Étienne scale.
Finally, I’m discussing collaborations with colleagues from the ILM (Institute of Light Matter), focusing on physical chemistry: understanding interactions, analyzing chemical reactions, and applying my expertise in coupling with mass spectrometry.

What particularly excites you about this field?

Chemistry! Trying to understand why things work the way they do, not otherwise. What still amazes me is that when working on different pollution remediation methods (plasma, photocatalysis, hot or cold catalysis, electrocatalysis), we start from seemingly simple systems: oxidation or reduction. But the products formed are hugely different depending on the case, just like the reaction mechanisms in the surface or gaseous phase. Connecting these systems to find a logic—that’s what excites me. Finding the logic in complex systems.

Why did you choose Ircelyon to continue your research?

For the team first, which is very friendly, dynamic, and offers good working conditions. The lab’s size also allows you to talk to many people, cross subjects, and methods, developing a broader perspective. There’s an excellent analytical park, and while you can propose a technique, it has its advantages, disadvantages, and—most importantly—limitations. The opportunities at Ircelyon push you to go beyond those limitations.

What personal or scientific challenge would you like to overcome through your work at Ircelyon?

It would be to better understand these systems and connect them more effectively. Technically, what’s missing now is the coupling with electrochemistry. More broadly, it’s about understanding chemical reactivity.

Do you have an anecdote to share or a memorable first impression since your arrival?

I love that there are so many young people around; it’s energetic! The atmosphere is great, people regularly bring in cakes… And the fourth-floor café room? A brilliant idea. It’s essential for daily life and for integrating into the team.

Outside of work, what are your favorite hobbies or activities?

First and foremost, I take care of my children: we go hiking, take walks together. I also do a lot of sports (athletics, swimming, etc.). My other passion is Breton culture. With my name and surname, it’s hard to hide it—I’m Breton! I speak Breton, I speak it to my children, and I transmit the language. I’m involved in associations to promote the Breton language.