Event interval: Single day event
Campus location: Bagley Hall (BAG)
Campus room: BAG 260
Accessibility Contact: chem59x@uw.edu
Event Types: Lectures/Seminars
Link: https://rodriguezlopez.chemistry.illinois.edu/

Putting a New Spin on the Electrochemistry of Oxygen: Nanoelectrochemistry, Spectroscopy, and Automated Analysis 

Professor Joaquín Rodríguez López – Chemistry, University of Illinois Urbana-Champaign

Elucidating and controlling the interfacial reactivity of oxygenated intermediates 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 techniques based on small electrodes, new spectroscopic methods, and the use of automated electrochemistry  to characterize intermediates such as reactive oxygen species (ROS) and to explore the converstion of oxygenated organics. I will talk about how we use electrochemical microscopy (SECM), a scanned probe technique capable of delivering high spatiotemporal and chemical redox resolution at active surfaces for generating ROS. 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. In my talk, I will describe the main features of our instrumental setup, applications to interface and bulk nanomaterials used in electrocatalysis and batteries, and emerging directions that amplify the role of hyphenated techniques such as Raman spectroscopy coupled to the SECM. I will highlight recent experiments describing the detection of highly reacting hydroxyl radical intermediates [1] the detection of oxygen evolution in degrading metal-oxide electrodes [2], the direct detection of singlet oxygen,[3] and the use of new graphene-on-metal substrates for electrochemical SERS and SEIRAS on carbon electrodes [4] and the exciting use of automated electrochemistry methods to better characterize electrocatalytic transformations involving oxygenated organic compounds, including TEMPO-catalyzed transformations of alcohols.[5]   
 
[1] Barroso-Martinez, J.S. et al. J. Am. Chem. Soc. 2022, 18896; [2] Mishra, A. J. Electrochem. Soc. 2022, 086501; [3] Mishra, A. et al, J. Am Chem. Soc. 2024, 8847; [4] Siddiqui, A.R. et al. Anal. Chem. 2024, 2435. [5] Pence, M.A. et al. Digital Discovery 2024, 1812.