Alkali Ion-Based Memristors for Neuromorphic Computing Applications Hong-Sub Lee Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Korea E-mail : h.s.lee@khu.ac.kr The matrix-vector multipliers combining analog memory (memristor) and crossbar array architecture (CAA) is the foremost scheme among the neuromorphic hardware currently considered. For implementing...
Abstract: Over the course of 3.5 billion years of evolution, living organisms have developed numerous functional structures. Notable examples include the superhydrophobic surfaces of micro/nano-structured leaves, the non-reflective surfaces of moth eyes, and the highly sensitive sensory organs of spiders. Understanding and mimicking these functional...
Electrochemical CO2 reduction reaction for sustainable chemical cycle Yun Jeong Hwang 1* 1Department of Chemistry, Seoul National University (SNU), Republic of Korea E-mail address: yjhwang1@snu.ac.kr Electrochemical CO2 reduction (CO2R) can be integrated with renewable energy sources and water can be utilized as a direct proton source which is promising to provide a sustainable net-zero carbon cycle. However, using water as the proton source causes undesired competitive hydrogen evolution reaction (HER), and thus it is crucial to control selectivity for CO2R. Various metal-based electrocatalysts have been investigated to convert CO2 to CO, formate, ethylene, ethanol, or other C2+ chemicals. Multiple reaction pathways and reaction intermediates are shared and thus product distribution is sensitively affected by nanostructured active sites both in a conventional H-cell as well as a membrane electrode assembly (MEA) electrolyzer. Understanding intrinsic and extrinsic factors are important to achieve selective CO2R to target product. In this talk, I will discuss efforts to understand the morphology changes of the nanocatalyst. Cu-based catalysts can experience morphology changes during the pre-treatment step and reduction reaction conditions, and increasing the domain boundaries can contribute to enhanced activity for CO2R over HER. In the GDE-based membrane-electrode-assembly (MEA) electrolyzer, increasing the surface roughness and grain boundaries have shown high selectivity for C2+ chemicals similar to the conventional H-Cell type electrolyzer. Meanwhile, from a practical point of view, researchers also propose direct conversion of the captured CO2 by the electrochemical process. We demonstrate that a Ni-N-C catalyst has high selectivity for electrochemical CO2 conversion to CO production due to the relatively high activation energy for HER compared to that of the CO2R-to-CO reaction. This contributes to increasing CO2 conversion efficiency even under low concentrations of available CO2 gas. In addition, the Ni-N-C was found to have low sensitivity to the type of alkali metal cation or the type of amine. Modulation of the catalyst-electrolyte interface can provide new opportunities to promote challenging catalytic reactions....
With the recent emergence of future mobility developments such as Urban Air Mobility (UAM), there has been an increasing interest in the development of materials suitable for these advancements. What might the specific requirements be for materials used in future mobility? Firstly, lightweight materials will be...
* This seminar will be held in Korean. ...
Electro-Mechanically Responsive Ionoelastomer Heterojunctions Hyeong Jun Kim Department of Chemical and Biomolecular Engineering, Sogang University, Seoul, South Korea Soft solids capable of conducting ions offer promise for the design of entirely new classes of highly deformable and bio-inspired devices. While resistive and capacitive ionic circuit elements are...
When shape optimization of engineering objects is conducted in the aerodynamic prospective, it is necessary to examine objects’ performance at various designs. One of the most widely used shape design methods in this purpose is to parameterize the given shape (frequently called the baseline design or...
* This seminar will be held in Korean. ...
