Operando Electrochemical Liquid-Cell STEM at Dynamic Catalyst Interfaces During CO2 Reduction

Electrocatalysis lies at the interface between materials science and electrochemistry and represents one of the most promising approaches for enabling renewable energy technologies to mitigate carbon emissions through the use of hydrogen fuel cells and the electrochemical reduction of CO₂. One of the key challenges is understanding how to achieve and sustain electrocatalytic activity under operating conditions for extended time periods, and such fundamental understanding calls for the use of time-resolve nanoscale <i>operando</i> analytical methods.¹<br/><br/>In this presentation, I will introduce our recent progress on developing <i>operando </i>electrochemical liquid-cell scanning transmission electron microscopy (EC-STEM), which simultaneously enables quantitative electrochemistry on microelectrodes and quantitative STEM based imaging, diffraction and spectroscopy.² <i>Operando</i> electrochemical 4D-STEM in liquid,³ driven by machine learning,⁴ has shown great potentials to interrogate complex structures of active sites of energy materials at solid-liquid interfaces.⁵ In particular, we will present our latest work on multimodal <i>operando</i> studies of combining EC-STEM and correlative synchrotron based X-ray methods^6,7 to elucidate the longstanding enigmatic nature of Cu active sites as Cu nanograins for selective CO₂ electroreduction.<br/>References:<br/>1. Y. Yang et al. <i>Curr. Opin. Electrochem</i>. 2023, 42, 101403.<br/>2. Y. Yang <i>et al</i>. <i>ACS Energy Lett</i>. 2023, 7, 1292.<br/>3. Y. Yang, <i>J. Am. Chem. Soc</i>. 2022, 144, 8927.<br/>4. C. Shi, Y. Han et al. <i>Npj Comput. Mater.</i> 2022, 8, 114.<br/>5. Y. Yang, <i>Nature</i> 2023, 614, 262.<br/>6. Y. Yang, <i>J. Am. Chem. Soc</i>. 2022, 144, 45698.<br/>7. J. Feijoo, Y. Yang et al. J. Am. Chem. Soc. 2023, 145, 20208