TY - JOUR A1 - Balderas-Xicohtencatl, R. A1 - Villajos Collado, José Antonio A1 - Casabán, J. A1 - Wong, D. A1 - Maiwald, Michael A1 - Hirscher, M. T1 - ZIF‑8 Pellets as a Robust Material for Hydrogen Cryo-Adsorption Tanks N2 - Cryoadsorption on the inner surface of porous materials is a promising solution for safe, fast, and reversible hydrogen storage. Within the class of highly porous metal−organic frameworks, zeolitic imidazolate frameworks (ZIFs) show high thermal, chemical, and mechanical stability. In this study, we selected ZIF-8 synthesized mechanochemically by twin-screw extrusion as powder and pellets. The hydrogen storage capacity at 77 K and up to 100 bar has been analyzed in two laboratories applying three different measurement setups showing a high reproducibility. Pelletizing ZIF-8 increases the packing density close to the corresponding value for a single crystal without loss of porosity, resulting in an improved volumetric hydrogen storage capacity close to the upper limit for a single crystal. The high volumetric uptake combined with a low and constant heat of adsorption provides ca. 31 g of usable hydrogen per liter of pellet assuming a temperature−pressure swing adsorption process between 77 K − 100 bar and 117 K − 5 bar. Cycling experiments do not indicate any degradation in storage capacity. The excellent stability during preparation, handling, and operation of ZIF-8 pellets demonstrates its potential as a robust adsorbent material for technical application in pilot- and full-scale adsorption vessel prototypes. KW - Hydrogen adsorption storage KW - Metal−organic frameworks KW - ZIF-8 KW - Cryoadsorption KW - Hydrogen Storage KW - MefHySto PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-569473 SN - 2574-0962 SP - 1 EP - 8 PB - ACS Publications CY - Washington DC AN - OPUS4-56947 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gugin, Nikita A1 - Villajos Collado, José Antonio A1 - Dautain, O. A1 - Maiwald, Michael A1 - Emmerling, Franziska T1 - Optimizing the Green Synthesis of ZIF-8 by Reactive Extrusion Using In Situ Raman Spectroscopy N2 - We report the scale-up of a batch solid synthesis of zeolitic imidazolate framework-8 (ZIF-8) for reactive extrusion. The crystalline product forms in the extruder directly under the mixture of solid 2-methylimidazole and basic zinc carbonate in the presence of a catalytic amount of liquid. The process parameters such as temperature, liquid type, feeding rate, and linker excess were optimized using the setup specifically designed for in situ Raman spectroscopy. Highly crystalline ZIF-8 with a Brunauer–Emmett–Teller (BET) surface area of 1816 m2 g–1 was quantitatively prepared at mild temperature using a catalytic amount of ethanol and a small excess of the linker. Finally, we developed a simple and comprehensive approach to evaluating the environmental friendliness and scalability of metal–organic framework (MOF) syntheses in view of their large-scale production. KW - Mechanochemistry KW - In situ Raman KW - Large-scale processing KW - Metal−organic frameworks KW - Twin-screw extrusion (TSE) PY - 2023 U6 - https://doi.org/10.1021/acssuschemeng.2c07509 SN - 2168-0485 VL - 11 IS - 13 SP - 5175 EP - 5183 PB - ACS Publications AN - OPUS4-57366 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -