Publication

Sustainable Energy Engineering Lab

Journal

Journal

  • 2024
  • Separators and Membranes for Advanced Alkaline Water Electrolysis
  • Dirk Henkensmeier,* Won-Chul Cho,* Patric Jannasch,* Jelena Stojadinovic,* Qingfeng Li,* David Aili,* and Jens Oluf Jensen* CHEMICAL REVIEWS accepted
  • Traditionally, alkaline water electrolysis (AWE) uses diaphragms to separate anode and cathode and is operated with 5–7 M KOH feed solutions. The ban of asbestos diaphragms led to the development of polymeric diaphragms, which are now the state of the art material. A promising alternative is the ion solvating membrane. Recent developments show that high conductivities can also be obtained in 1 M K…
  • 2020
  • Preparation of boron-carbide-supported iridium nanoclusters for the oxygen evolution reaction
  • Jahowa Islam, Sang-Kyung Kim, Hyun-Seok Cho, Min-Joong Kim, Won-Chul Cho, Chang-Hee Kim Electrochemistry Communications Accepted
  • Reducing the iridium loading for the oxygen evolution reaction (OER) is one of the main challenges of polymer electrolyte membrane water electrolysis (PEMWE). This study introduces grape-like iridium nanoclusters supported on boron carbide (B4C) which increase iridium utilization compared to a non-supported iridium catalyst. A simple chemical reduction method with NaBH4 as a reducing agent was use…
  • 2020
  • Renewable methanol synthesis from renewable H2 and captured CO2: How can power-to-liquid technology be economically feasible?
  • Boreum Lee, Hyunjun Lee, Dongjun Lim, Boris Brigljević, Wonchul Cho, Hyun-Seok Cho, Chang-Hee Kim, Hankwon Lim Applied Energy Accepted
  • With the growing concern about environmental issues including high CO2 emission, which is the main contributor to global warming resulting in climate change, CO2 utilization technologies have received much attention. Among diverse technologies, renewable methanol synthesis using H2 generated from the water electrolysis and the CO2 captured from various industrial processes as well as the atmospher…
  • 2021
  • Sacrificial species approach to designing robust transition metal phosphide cathodes for alkaline water electrolysis in discontinuous operation
  • Ik-Sun Kim, Hyun-Seok Cho, MinJoong Kim, Hyun-Jung Oh, Sang-Yeon Lee, Yong-Kul Lee, Changsoo Lee, Jae Hun Lee, Won Chul Cho, Sang-Kyung Kim, Jong Hoon Joo, Chang-Hee Kim Journal of Materials Chemistry A Accepted
  • The degradation of amorphous cobalt phosphides (CoPx) as an electrocatalyst for the hydrogen evolution reaction (HER) is studied in the discontinuous operation of alkaline water electrolysis cells (AWEs). Although amorphous CoPx shows a 100-fold enhancement in HER activity over nickel, the kinetic current for the HER is decreased after discontinuous operation. Under the off condition, the cathode …
  • 2021
  • Multi-Layered Sintered Porous Transport Layers in Alkaline Water Electrolysis
  • SANG HO YEOM, YOUNG HWA YUN, SEUNGWOOK CHOI, JIHEE KWON, SECHAN LEE, JAE HUN LEE, CHANGSOO LEE, MINJOONG KIM, SANG-KYUNG KIM, SUKKEE UM, CHANG-HEE KIM, WON CHUL CHO, HYUN-SEOK CHO Transactions of the Korean hydrogen and new energy society Accepted
  • The porous transport layer (PTL) is essential to effectively remove oxygen and hydrogen gas from the electrode surface at high current density operation conditions. In this study, the effect of PTL with different characteristics such as pore size, pore gradient, interfacial coating was investigated by multi-layered sintered mesh. A water electrolysis single cell of active area of the 34.56 cm 2 wa…
  • 2023
  • Green hydrogen to tackle the power curtailment: Meteorological data-based capacity factor and techno-economic analysis
  • Joungho Park, Kyung Hwan Ryu, Chang-Hee Kim, Won Chul Cho, MinJoong Kim, Jae Hun Lee, Hyun-Seok Cho, Jay H Lee Applied Energy Accpeted
  • Hydrogen production through water electrolysis stands as a potential remedy for the problem of curtailment, which refers to the deliberate downward adjustment of output power below capacity for the purpose of balancing supply and demand. This study demonstrates how comprehensive system modeling can be used to a priori assess the economics of producing green hydrogen from curtailed renewable energy…
  • 2023
  • A study on the effect of TiO2 nanoparticle size on the performance of composite separators in alkaline water electrolysis
  • Muhammad Farjad Ali, Hyun-Seok Cho, Christian Immanuel Bernäcker, Justin Albers, Choi Young-Woo, MinJoong Kim, Jae Hun Lee, Changsoo Lee, Sechan Lee, Won-Chul Cho Journal of Membrane Science Accpeted
  • Composite separators comprising ceramic filler and thermoplastic polymer are widely used in alkaline electrolyzers due to their stability in harsh conditions. The ceramic filler should possess high chemical stability and strong interaction with the polymer binder. TiO2 is a good filler candidate due to its hydrophilicity and potential capabilities. However, the impact of TiO2 size on composite sep…
  • 2022
  • Zirconia Toughened Alumina-Based Separator Membrane for Advanced Alkaline Water Electrolyzer
  • Muhammad Farjad Ali, Hae In Lee, Christian Immanuel Bernäcker, Thomas Weißgärber, Sechan Lee, Sang-Kyung Kim, Won-Chul Cho Polymers Accepted
  • Hydrogen is nowadays considered a favorable and attractive energy carrier fuel to replace other fuels that cause global warming problems. Water electrolysis has attracted the attention of researchers to produce green hydrogen mainly for the accumulation of renewable energy. Hydrogen can be safely used as a bridge to successfully connect the energy demand and supply divisions. An alkaline water ele…
  • 2021
  • Advanced Zirfon-type porous separator for a high-rate alkaline electrolyser operating in a dynamic mode
  • Hae In Lee, Muhammad Mehdi, Sang Kyung Kim, Hyun Seok Cho, Min Joong Kim, Won Chul Cho, Young Woo Rhee, Chang Hee Kim Journal of Membrane Science Accepted
  • Porous separators have been widely used in classical alkaline electrolysers. The development of an advanced separator with low ohmic resistance and hydrogen permeability is essential for operating a high-rate alkaline electrolyser in a dynamic mode. In this study, we report the synthesis of a Zirfon-type separator with a reduced ohmic resistance of 0.10 Ω cm2 and hydrogen permeability of 0.2 × 10−…
  • 2020
  • The synthesis of a Zirfon‐type porous separator with reduced gas crossover for alkaline electrolyzer
  • Hae In Lee, Dao Thi Dung, Jieun Kim, Jae Hun Pak, Sang Kyung Kim, Hyun Seok Cho, Won Chul Cho, Chang Hee Kim International Journal of Energy Research Accepted
  • The rapid expansion of renewable energy sources presents a great challenge to balance the electric grid due to their intermittent and volatile nature. The surplus energy generation cannot be used or sold so that it is curtailed in order to maintain the grid balance. The excess power can be converted into a gaseous energy carrier, hydrogen via power-to-gas technology. Alkaline water electrolysis ca…
Redox reactivity of titania‐doped YSZ‐promoted iron‐based oxygen carrier over multiple redox cycles for chemical looping reforming of methane and hydrogen production
Author
Jun Kyu Lee, Hae In Lee, Hyun Seok Cho, Chang Hee Kim, Won Chul Cho
Journal
International Journal of Energy Research
Status
Accepted
Page
4919-4932
Year
2020
Chemical looping using methane offers the potential for producing syngas or hydrogen with intrinsic separation of CO2. An ilmenite (FeTiO3)-based oxygen carrier is a suitable oxygen carrier for methane oxidation because of good reactivity and low cost. However, it underwent a phase separation during repeated redox cycles, thereby resulting in the decrease in the reactivity. Therefore, it is necessary to develop a TiO2-supported iron oxide composite with high redox stability and reactivity. In this study, we synthesize a titania-doped YSZ (Y0.20Ti0.15Zr0.65O1.90)-promoted iron-based oxygen carrier. Inert material (ZrO2), pure ionic material (YSZ), and electronic conductive material (TiO2) are used as support materials for comparison. It is found that the Y0.20Ti0.15Zr0.65O1.90 promotes iron-based oxygen carrier showed the best performance (27%/min to achieve 66% conversion) in methane oxidation in TGA experiment, high syngas selectivity in fixed bed reactor, and the redox stability over 100 redox cycles. Meanwhile, the other oxygen carriers show low reactivity and the morphological changes (iron oxide layer) and/or the phase decomposition (ie, YSZ → Y2O3 and ZrO2 and Fe2TiO5 → Fe2O3 and TiO2). The enhanced reactivity and stability are mainly ascribed to the mixed ionic-electronic conductivity and the redox stability of titania-doped YSZ in the single-phase fluorite region.