Title: Operando Insights into Catalyst-Electrolyte Interfaces for Electrochemical CO₂ and N₂ Reduction

Abstract: Transitioning to sustainable energy solutions requires innovative approaches to producing essential chemicals like ethanol and ammonia. Electrochemical methods offer a promising alternative by using electricity, ideally from renewable sources, to convert carbon dioxide and nitrogen into valuable products. However, making these processes efficient and selective remains a challenge. This work employs advanced operando spectroscopic techniques to investigate catalyst dynamics at the electrode-electrolyte interface, offering real-time insights into reaction mechanisms under reaction conditions. For CO2 reduction (CO2RR), time-resolved X-ray absorption spectroscopy (XAS)1 and surface-enhanced Raman spectroscopy (SERS)2 revealed how pulsed electrochemical techniques modulate Cu oxidation states and hydroxide co-adsorption, enhancing ethanol selectivity. Alloying Cu with Ag3 or Zn4 improved catalytic stability and promoted favorable reaction pathways, highlighting the importance of dynamic catalyst restructuring under operating conditions. For lithium-mediated nitrogen reduction to ammonia (LiNRR), operando Raman spectroscopy tracked the formation and evolution of the solid electrolyte interphase (SEI), showing how electrolyte composition influences lithium deposition, nitrogen activation, and ammonia yield. Transitioning from LiClO4 to LiFSI in tetrahydrofuran/ethanol-based solvents significantly lowers the lithium plating potential, reducing side reactions such as hydrogen evolution and improving overall reaction performance.5 By integrating operando insights with strategic catalyst and electrolyte design, this work advances the understanding of dynamic interactions at the catalyst-electrolyte interface for both CO2RR and NRR.

Bio: Dr. Antonia Herzog is a researcher in renewable electrochemical energy conversion. She earned her PhD with distinction from the Fritz Haber Institute of the Max Planck Society under Prof. Beatriz Roldán Cuenya, where her work on Cu-based catalysts provided key insights into the formation of multi-carbon products during CO₂ electroreduction. Dr. Herzog’s innovative approach, combining insights from operando Raman spectroscopy and synchrotron X-ray methods, has redefined the field by linking catalyst structure to real-time reactivity. Currently, as a postdoctoral associate at MIT’s Electrochemical Energy Lab under Prof. Yang Shao-Horn, Dr. Herzog is expanding her research to tackle key challenges in nitrogen activation for ammonia synthesis, lithium interfaces, and direct CO₂ conversion into food. With around 25 publications in prestigious journals, including Nature Communications, Angewandte Chemie, and Energy & Environmental Science, she has made significant contributions to advance electrocatalysis.