Aram Yoon (Shell Energy Transition Center, Amsterdam)

Résumé : Electrocatalysis plays a pivotal role in various energy conversion and storage applications, including fuel cells, electrolyzers, and batteries. It facilitates the conversion of chemicals from one form to another, making it essential for clean and sustainable energy technologies. Transition metal oxides show great promise in this regard, as they are abundant on Earth and can modify their electrical and chemical properties by adjusting their oxidation state through surface and interface engineering. To effectively harness these materials in energy conversion devices, it is imperative to gain insights into how catalysts’ structures behave in working environments, as this significantly influences chemical conversions and the catalysts’ own chemical status. However, investigating the structure and chemistry of electrocatalysts under electrochemical reaction conditions is a challenging endeavor. Electrochemical systems involve reactions and transformations occurring at multiphase boundaries, including solid-solid and solid-liquid interfaces. This complexity necessitates the use of diverse techniques to probe these interfaces, further complicated by the need to maintain the electrolyte and applied potential.

In my presentation, I will delve into the behavior of Cu₂O catalysts under dynamic reaction conditions, employing a multimodal approach centered on in situ Electrochemical Cell Transmission Electron Microscopy (EC-TEM). This approach will focus on two conversion reactions involving Cu₂O catalysts: electrochemical CO₂ reduction and nitrate reduction. Through this investigation, I will demonstrate structural changes of Cu₂O catalysts during redox reactions. The primary emphasis will be on correlating various operando techniques, such as X-ray absorption microscopy and spectroscopy, with electrochemical characterization to gain a comprehensive understanding of how structural heterogeneity impacts catalysis.

Pour tout contact : Maria Letizia De Marco (0388107028 – maria-letizia.demarco@ipcms.unistra.fr)