▷ 제목: Nanoscale Imaging of Catalysts in Energy Conversion System

▷ 내용: Solid-solid and solid-liquid interfaces are key components for diverse systems of electrocatalytic chemical conversion and rechargeable battery. Critical electrochemical reactions at the diverse interfaces in those systems occur at the nanometer length scale. Despite the importance of the interfacial reactions, a lack of analytical tools that can characterize structural changes at the nanoscale level has hindered fundamental mechanistic understating of them. The recent development of transmission electron microscopy (TEM) is gaining attention as a new tool to directly observe electrochemical reactions that occur in solid-solid and solid-liquid interfaces with high resolution. Here, we introduce a few examples where advanced TEM, in conjunction with other in situ characterization techniques, directly reveals important reactions at the interfaces of electrocatalysts and the electrolyte. Special efforts have been made to improve liquid-phase and in-situ TEM as a reliable method for monitoring electrochemical process of metal catalysts in realistic condition. With this approach, direct TEM observation successfully reveals how catalysts respond to incoming molecules and electrochemical cycles in accelerated stress test of fuel cell reaction in nanoscale spatial resolution. In situ TEM observations are also extended to investigation of important processes in diverse types of catalyst such as etching, CO2 reduction of metal catalysts, and HER reaction of MoS2.