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Commercial-scale glycerol valorization using surface-modified copper cobalt oxide catalyst in high-capacity anion exchange membrane electrolyzer

2026-02-28T15:00:00Z

Title: Commercial-scale glycerol valorization using surface-modified copper cobalt oxide catalyst in high-capacity anion exchange membrane electrolyzer Author(s): Yoon, Ki-Yong; Hwang, Seon Woo; Roh, Hee Yoon; Gu, Jiwon; Lee, Kyung-Bok; Jeong, Jaehoon; Oh, Dongrak; Kwak, Myung-Jun; Yu, Je Min; Kim, Dohyung; Lee, Ji-Hoon; Choi, Sung Mook; Lim, Hankwon; Lee, Hosik; Jang, Ji-Wook; Yang, Juchan Abstract: Interest in electrochemical glycerol oxidation reactions (GORs) continues to grow as a promising strategy for hydrogen production. By replacing the oxygen evolution reaction (OER), GOR reduces energy consumption while generating hydrogen at the cathode and value-added formate at the anode, offering techno-economic advantages over conventional water electrolysis. However, its practical implementation is still hindered by reliance on precious metal catalysts and performance losses in scaled-up systems. Here, we synthesized a non-precious CuCo oxide (CCO) electrocatalyst at a tens-of-grams scale through co-precipitation and simple surface treatment. When applied to an anion exchange membrane (AEM) electrolyzer, the modified CuCo oxide achieved 110 mA cm-2 at 1.31 Vcell using a 7 cm2 non-precious GOR anode with 96% formate selectivity. The system was further scaled to a 79 cm2 anode, delivering 3.2 A at 1.31 Vcell. This study demonstrates a practical and economically favorable pathway for scalable hydrogen production via glycerol valorization in AEM electrolyzers.

Conceptual CFD design of a molten salt-heated ammonia cracking reactor for efficient hydrogen production

2026-03-31T15:00:00Z

Title: Conceptual CFD design of a molten salt-heated ammonia cracking reactor for efficient hydrogen production Author(s): Gu, Jiwon; Kim, Youngmin; Im, Younghwan; Kim, Min Sik; Ni, Aleksey; Chae, Ho-Jeong; Lim, Hankwon Abstract: As hydrogen demand increases in the transition toward a carbon-neutral society, solutions for hydrogen storage and transportation are necessary. Among the various options, ammonia is a promising hydrogen carrier due to its high volumetric density, and ammonia cracking process is indispensable to regenerate hydrogen. However, because ammonia cracking is energy-intensive, the development of large-scale ammonia cracking reactors with energy efficient heat management system is essential to ensure reliable hydrogen supply to satisfy hydrogen demand. In this work, a numerical model of shell-and-tube ammonia cracking reactor suitable for both centralized and distributed type plants is developed, employing molten salt as the heat transfer fluid to achieve uniform and efficient heat supply. When the ammonia temperature is sufficiently raised, conversion exceeding 75% and 83.1% of energy efficiency are achieved, while the molten salt exhibited only 22.6% temperature drop compared with the corresponding gas flow temperature rise. The reactor performances for various tube lengths or diameters yield conversion rates from 65 to 88%, indicating that a molten salt-heated shell-and-tube ammonia cracker can be designed as a compact reactor. Furthermore, sensitivity analyses of key parameters, including inlet temperatures, pressure, and space velocity, are found to have strong influence on temperature profiles and reaction progress, and the small multi-tubular model remains the performance well similar for the singular tube system. This study demonstrates for the first time via a CFD conceptual design of ammonia cracker, that molten salt heating is viable for maintaining uniform temperature gradients (<40 degrees C) and achieve >65% NH(3 )conversion rate in compact ammonia cracking reactor under industrial-grade gas hourly sapce velocity (GHSV), providing a viable design pathway for demonstration of large-scale ammonia crackers and contributing to the realization of an integrated hydrogen value chain.

Q-learning-based stochastic model predictive control for green ammonia production

2026-03-31T15:00:00Z

Title: Q-learning-based stochastic model predictive control for green ammonia production Author(s): Park, Hyun Min; Oh, Tae Hoon; Lee, Jong Min Abstract: Green ammonia production systems powered by intermittent renewable energy must meet periodic demand under tight unit and storage constraints. We propose Q-learning-based stochastic model predictive control, a methodology integrating a stochastic model predictive control framework with a Q-function as the terminal cost. The proposed method explicitly enforces hard constraints, effectively manages both short-term and longterm disturbances, and offers significant advantages in terms of on-line computational speed. Simulation results show that the proposed method outperforms Nonlinear Model Predictive Control, Double Deep Q-Network, and Q-learning-based Model Predictive Control baselines. The proposed method achieves the lowest total cost, minimal soft constraint penalties, and eliminates both tank overflow and ammonia demand shortfall, enabling practical, real-time operation.

Long-range transport of short-lived nitrogen dioxide in East Asia

2025-11-30T15:00:00Z

Title: Long-range transport of short-lived nitrogen dioxide in East Asia Author(s): Baek, Seung-hee; Lee, Hyo-jung; Jo, Hyun-young; Kim, Cheol Hee; Park, Min-jun; Kim, Jongmin; Bak, Juseon; Lee, Hanlim; Jung, Yeonjin; Park, Junsung; Woo, Jung-hun; Kim, Jinseok; Park, Rokjin J.; Chang, Limseok; Song, Chang-Keun Abstract: This study explores the broader spatial influence of nitrogen dioxide (NO₂) over East Asia by integrating satellite and aircraft observations with chemical transport and trajectory model analyses. Tropospheric NO₂ column densities observed by the TROPOspheric Monitoring Instrument (TROPOMI) over the Yellow Sea—located between China and South Korea—are found to be 3.2 times higher in winter than the annual average, highlighting the role of prevailing westerlies in facilitating regional-scale transport during the cold season. Additional insights into the diurnal dynamics of NO₂ transport are provided by hourly observations from the Geostationary Environment Monitoring Spectrometer (GEMS). To further examine the mechanisms responsible for this transport, satellite-based evidence is complemented by in situ aircraft measurements and chemical transport model simulations. Aircraft profiles over the Yellow Sea confirm that NO₂ can be extensively transported at altitudes of 1–2 km under favorable meteorological conditions. Model results indicate that the lifetime of NOₓ in major urban areas—such as the Beijing–Tianjin–Hebei region and the Seoul Metropolitan Area—can be extended from several hours to 1–3 days, depending on meteorological conditions. Trajectory analyses further suggest that NOₓ originating from East Asia can reach downwind regions across adjacent seas within 12–24 h. These findings underscore the importance of accounting for the long-range transport of short-lived pollutants in the development of national air quality management strategies. © 2025 The Authors