"O all Over: New Electrochemical Probes for Elucidating the Roles of Oxygen at Interfaces for Energy Storage and Conversion"

ABSTRACT

Elucidating and controlling interfacial reactivity is key to a broad scope of electrochemical studies of catalysts, sensors, and energy storage media. I will present a modern approach to understanding the electrochemical interface using scanning electrochemical microscopy (SECM), a scanned probe technique capable of delivering high spatiotemporal and chemical redox resolution at active surfaces. SECM uses an electrochemical probe to detect and quantify species (e.g. discharged products, homogeneous and heterogeneous intermediates) and the kinetics of processes (e.g. heterogeneous rate constants) through the use of highly localized electrochemical techniques deployed by such probe. [1,2] Our group has expanded the toolbox of SECM techniques to include modes such as Surface Interrogation SECM, where the surface coverage and dynamics of oxygenated adsorbed intermediates are explored, and the introduction of simultaneous and co-localized SECM-Raman investigations of a variety of interfaces. [3,4] Such in situ approaches give us insight regarding the reactivity of individual reacting sites within bulk electrodes, including their evolution during operation, and enable the construction of sensible structure–function correlations and electroanalytical models. In my talk, I will describe the main features of our instrumental setup, applications to interface and bulk nanomaterials, and emerging directions that amplify the role of hyphenated techniques coupled to the SECM into a highly versatile toolbox for manifold electrochemical processes. I will highlight recent experiments describing the detection of highly reacting hydroxyl radical intermediates [5] and the detection of oxygen evolution in degrading metal-oxide electrodes [6], which we hope will have an impact on our ability to tailor interfaces for energy storage and catalysis. [1] Counihan, M. et al. ChemElectroChem 2019, 3507; [2] Krumov, M.R., et al. Anal. Chem. 2018, 3050; [3] Schorr, N.B. et al. Anal. Chem. 2018, 7848; [4] Schorr, N.B. et al. Curr. Op. Electrochem. 2018, 89. [5] Barroso-Martinez, J.S. et al. J. Am. Chem. Soc. 2022, 18896; [6] Mishra, A. J. Electrochem. Soc. 2022, 086501.

BIOGRAPHY

Joaquín Rodríguez-López is an Associate Professor of Chemistry at the University of Illinois Urbana-Champaign. Joaquin’s group combines interests in electroanalytical chemistry and energy materials by developing chemically sensitive methods for studying ionic and electronic reactivity in nanostructures, highly localized surface features, and ultra-thin electrodes. Recognition to Joaquin’s work has come through awards such as the Zhaowu Tian Prize for Energy Electrochemistry by the International Society of Electrochemistry (2021), The Arthur Findeis Award for Achievements by a Young Analytical Scientist by the ACS DAC (2020), the Society of Electroanalytical Chemistry Royce W. Murray Young Investigator Award (2017), a Toyota- Electrochemical Society Young Investigator Fellowship (2017), the Sloan Research Fellowship (2016), and the East Central Illinois ACS Chapter Distinguished Service Award (2016), amongst other awards. The group of his work has been highlighted in the media by The Analytical Scientist as a 40-under-40 investigator (2022) and by Science News 10 Scientists to Watch (2018). Rodríguez-López is a recognized leader in electroanalysis, summing over 100 invited national and international presentations, over 100 publications and book chapters, leadership within the DOE JCESR Energy Hub and a thriving electrochemical program that gives back through educational activities such as his staple “Electrochemistry Bootcamp” organized at UIUC and which teaches laboratory skills to broad audiences.