In Situ Study of Electrified Solid-Liquid Interfaces using Liquid Cell TEM combining with other Advanced EM Techniques

Electrified solid-liquid interfaces play a key role in various electrochemical processes relevant to electrocatalysis, batteries, and supercapacitors. The electron and mass transport at the electrified interfaces may result in structural modifications that remarkably influence the reaction pathways.<br/>Extensive studies of the electrified solid-liquid interfaces have been on the physisorption and chemisorption of species at the interfaces. However, the microscopic details of electrified solid-liquid interfaces, especially their atomic-scale structural evolution during electrochemical reactions, remain unclear. In situ transmission electron microscopy (TEM) allows tracking of the evolution of individual nanocatalysts during reactions. With our development of advanced high resolution electrochemical liquid cells for TEM, we monitor the atomic dynamics of electrified solid-liquid interfaces during Cu-catalyzed CO₂ electroreduction reactions. Other techniques, such as, Cryo-EM of certain reaction states by fast freezing of the same liquid cell, chemical analysis with energy dispersive x-ray spectroscopy (EDS) and electron energy loss spectroscopy (EELS)<br/>Our systematic study unveils fascinating atomic dynamics as well as structural and chemical evolution of the electrified solid-liquid interfaces. The combination of experimental observation and theoretical calculations reveals an amorphization-mediated restructuring mechanism resulting from charge-activated surface reactions with the electrolyte. Our results hold significant implications for utilizing interphases to control catalyst surface restructuring, thus tuning the catalytic reactions.