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Proton-conducting copper-based MOFs for fuel cells

2025-12-18T02:42:21Z

Title: Proton-conducting copper-based MOFs for fuel cells Author(s): Kim, Byong June; Park, Sun Ho; Diaz-Ramirez, Mariana Lizeth; Jeong, Nak Cheon Abstract: Metal-organic frameworks (MOFs) are emerging as promising alternatives for proton-conductive materials due to their high porosity, large surface area, stability, and relatively low cost. Among these, copper-based MOFs (Cu-MOFs) stand out with unique advantages, including open metal sites, variable valence states, and strongly electrophilic Cu centers. In this review, we discuss recent advances and developments in the use of Cu-MOFs as proton-conductive materials, with a particular focus on their application as proton exchange membranes (PEMs). We introduce the most common strategies employed to date and review the key features that have contributed to the construction of efficient proton transport pathways in Cu-MOFs. Additionally, we review PEMs fabricated via direct thin-film deposition or as mixed-matrix membranes (MMMs) incorporating Cu-MOF fillers. Finally, we address the challenges that must be overcome in the coming years to develop more robust Cu-MOFs and to create more efficient thin films and Cu-MOF-based MMMs.

Gas-flow activation of MOFs: unlocking efficient catalysis through dynamic bonding

2025-07-25T03:35:33Z

Title: Gas-flow activation of MOFs: unlocking efficient catalysis through dynamic bonding Author(s): Diaz-Ramirez, Mariana Lizeth; Park, Sun Ho; Rivera-Almazo, Marcos; Medel, Erika; Peralta, Ricardo A.; Ibarra, Ilich A.; Vargas, Rubicelia; Garza, Jorge; Jeong, Nak Cheon Abstract: Metal-organic frameworks (MOFs), characterized by dynamic metal-ligand coordination bonding, have pivotal roles in catalysis, gas storage, and separation processes, owing to their open metal sites (OMSs). These sites, however, are frequently occupied by Lewis-base solvent molecules, necessitating activation to expose the OMSs for practical applications. Traditional thermal activation methods involve harsh conditions, risking structural integrity. This study presents a novel ‘gas-flow activation’ technique using inert gases like nitrogen and argon to eliminate these coordinating solvent molecules at low temperatures, thereby maintaining the structural integrity of MOFs. We specifically explored this method with HKUST-1, demonstrating that gas-flow activation at mild temperatures is not only feasible but also superior in efficiency compared to the conventional thermal methods. This approach highlights the potential for safer, more efficient activation processes in MOF applications, making it a valuable addition to the repertoire of MOF activation techniques. This activation function of inert gas flow allows HKUST-1 as a catalyst for the hydrogenation of acetophenone even at room temperature. In addition, it is demonstrated that this ‘gas-flow activation’ is broadly applicable in other MOFs such as MOF-14 and UTSA-76. Furthermore, the findings reveal that dynamic coordination bonding, the repeating transient dissociation-association of solvent molecules at OMSs, are key mechanisms in facilitating this activation, pointing towards new directions for designing activation strategies that prevent structural damage. © 2025 The Royal Society of Chemistry.

Time-efficient atmospheric water harvesting using Fluorophenyl oligomer incorporated MOFs

2025-07-25T02:42:25Z

Title: Time-efficient atmospheric water harvesting using Fluorophenyl oligomer incorporated MOFs Author(s): Kang, Min Seok; Heo, Incheol; Park, Sun Ho; Bae, Jinhee; Kim, Sangyeop; Kim, Gyuchan; Kim, Byung-Hyun; Jeong, Nak Cheon; Yoo, Won Cheol Abstract: Adsorption-based atmospheric water harvesting (AWH) has the potential to address water scarcity in arid regions. However, developing adsorbents that effectively capture water at a low relative humidity (RH < 30%) and release it with minimal energy consumption remains a challenge. Herein, we report a fluorophenyl oligomer (FO)-incorporated metal-organic framework (MOF), HKUST-1 (FO@HK), which exhibits fast adsorption kinetics at low RH levels and facile desorption by sunlight. The incorporated fluorophenyl undergoes vapor-phase polymerization at the metal center to generate fluorophenyl oligomers that enhance the hydrolytic stability of FO@HK while preserving its characteristic water sorption behavior. The FO@HK exhibited vapor sorption rates of 8.04 and 11.76 L kg-1MOF h-1 at 20 and 30% RH, respectively, which are better than the state-of-the-art AWH sorbents. Outdoor tests using a solar-driven large-scale AWH device demonstrate that the sorbent can harvest 264.8 mL of water at a rate of 2.62 L kg-1MOF per day. This study provides a ubiquitous strategy for transforming water-sensitive MOFs into AWH sorbents. © 2024. The Author(s).

Hydroquinone-treated Cu3(BTC)2: a mixed-valence Cu(i/ii) MOF catalyst for efficient cycloadditions

2025-07-25T02:42:24Z

Title: Hydroquinone-treated Cu3(BTC)2: a mixed-valence Cu(i/ii) MOF catalyst for efficient cycloadditions Author(s): Park, Sun Ho; Kim, Hye Mi; Diaz-Ramirez, Mariana Lizeth; Lee, Sunggi; Jeong, Nak Cheon Abstract: We present mixed-valence Cu(I)1Cu(II)2(BTC)2 [henceforth Cu(I/II)-HKUST-1], post-synthetically prepared via the hydroquinone (H2Q) treatment of Cu(II)3(BTC)2 (also referred to as HKUST-1) and its subsequent catalytic activity.This Cu(I/II)-HKUST-1 exhibits exceptional structural integrity and superior catalytic performance in the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction between phenylacetylene and benzyl azide.These findings highlight the potential of mixed-valence Cu-based MOFs as effective and sustainable heterogeneous catalysts for organic transformations, paving the way for future advancements in MOF-based catalysis. © The Royal Society of Chemistry 2024.