Electrocatalyst Discovery Laboratory (EDL)

The efficiency of energy conversion (electrocatalysis for fuel cell, water electrolyzer and CO2 reduction) and energy storage (organic, aqueous, and solid state electrolyte battery) is almost entirely determined by the electrochemical interfacial property that controls the transfer rate of interfacial charges and various types of interactions based on fundamental electrochemistry. However, the importance of electrochemical interfaces, generally electrode/electrolyte interfaces, is often disregarded, and most studies have focused on either the electrode itself or the electrolyte as a separate field, thereby hindering their application to electrochemical energy conversion and storage devices. Considering that the overall electrochemical performance is entirely determined by ‘how to understand and design an interface’ , my research group aims to elucidate the “fundamental electrochemical interface at the atomic level by using well-controlled methods” based on fundamental electrochemistry, surface science approaches, and in situ techniques.

In situ analyses have recently received significant attention because the electrode undergoes significant changes during electrochemical reactions, affecting the overall electrochemical performance. The reversible structure change and dynamic reconstruction are important factors for electrochemical performance in various electrochemical systems. However, the conditions for in situ analysis do not represent the actual electrochemical environment; hence, obtaining reliable data is challenging. Furthermore, it is difficult to determine the behavior of a very sensitive surface without considering the cell design on the basis of purpose and conditions. Using unique cell design with rich experience, our group pursues investigation of electrochemical interface issues with various types of electrodes, from single crystals to nanoparticles in various time frames, from a steady-state to transient state (~ s).

My research group will focus on defining and investigating new types of activity and stability. As part of my ongoing project, ‘dynamic stability’ has been first demonstrated by the dynamic exchange of active sites on host materials. Dynamic exchange indicates continuous active site dissolution during reaction and redeposition on the host material, thus maintaining dynamic equilibrium on the electrochemical interface, which is different from the static stability. The main feature distinguished by classical stability is that it can be achieved by interfacial engineering. Without an active element in the electrolyte, the equilibrium cannot be obtained and, eventually, loses activity. When active elements exist in the electrolyte, the active site can be vigorously regenerated, suggesting that dynamic stability can be achieved by ‘electrochemical interface design’ between the electrode and electrolyte. Based on the fundamental understanding of atomic & molecular level understanding of electrochemical double layers, my group focus on development of energy and environmental application including 'fuel cells', 'water electrolyzer', 'electrochemical fuel production' (CO2 reduction & Ammonia production) and 'various electrolyte (aqueous, organic and solid state) battery'.

While I emphasize how fundamental understanding of atomistic level features in well-defined model study is important, it is not that easy to bridge the gap between fundamental knowledge and actual application. Bridging the gap between fundamental understanding from model study and real application level will be replenished by the fundamental research on ‘application-oriented fundamental model study’. It is really important for our research goal that not only how to contribute application fields as fundamental scientist but also expand research field from solid/liquid interface to various interface (polymer/solid, solid/solid) to solve energy and environmental problem. For that reasons, we would like to vigorously collaborate with experts in polymer science, nanoscience, energy system and theoretical science for industrial application

Hydrogen cycle-Fuel cell, Water electrolysis, LOHC (liquid organic hydrogen carrier)

Carbon cycle- CO2 conversion to value-added chemicals

Energy storage- next-generation energy storage systems