Component & Size-Tunable Metal Nanoparticle via Ultrafast Non-Equilibrium Synthesis—Design of Electrocatalysts for High-Performance Energy Conversion Systems

Metal nanoparticles (MNPs) are one of the most attractive materials in diverse applications due to their high electronic and catalytic activity. It has been reported that MNP engineering such as alloying, controlling particle size and formation density can derive unexpected effects leading to high catalytic performance. Unfortunately, in previous methods, alloying is possible only with thermodynamically miscible combinations of metals, and phase separation occurs as the number of the metals is increased due to the increased instability. Furthermore, the unavoidable aggregation of MNPs from particle migration and coalescence and Ostwald ripening during synthesis process result in ununiform NP size and density on the supports which cause low performance and reproducibility. Thus, the development of a universal and effective method for MNP engineering is highly demanded.<br/>In this presentation, we demonstrate a general strategy to overcome the abovementioned obstacles by adopting the carbothermal shock (CTS) method for electrocatalytic energy conversion systems. Immiscible metal alloying and multi-metallic NPs (&gt;4 elements) can be fabricated with high uniformity within 1 second through ultrafast heating/cooling process. Based on the CTS method, the modulation of support materials is simultaneously conducted to develop a full electrode system for high energy conversion efficiency. As the result, we present diverse electrocatalyst designs (i.e. Ru-Cu alloy on 3D carbon foam, Pd on boron nitride nanotube and Cu on cellulose) for electrocatalytic energy conversion systems to move up Net-Zero-World ecosystem; such as carbon dioxide (CO₂) reduction to ethylene (C₂H₄) and nitrogen (N₂) reduction to ammonia (NH₃).