Balderas-Xicohtencatl Rafael, Villajos Jose A, Casabán Jose, Wong Dennis, Maiwald Michael, Hirscher Michael
Max Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569Stuttgart, Germany.
Division Process Analytical Technology, Bundesanstalt für Materialforschung und -prüfung (BAM), Richard-Willstaetter Str. 11, 12489Berlin, Germany.
ACS Appl Energy Mater. 2023 Feb 1;6(18):9145-9152. doi: 10.1021/acsaem.2c03719. eCollection 2023 Sep 25.
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.
多孔材料内表面的低温吸附是一种安全、快速且可逆的储氢解决方案。在高度多孔的金属有机骨架材料类别中，沸石咪唑酯骨架材料（ZIFs）表现出高热稳定性、化学稳定性和机械稳定性。在本研究中，我们选择了通过双螺杆挤出机械化学合成的ZIF-8粉末和颗粒。在两个实验室中使用三种不同的测量装置对77 K和高达100 bar压力下的储氢容量进行了分析，结果显示出高重现性。将ZIF-8制成颗粒会增加堆积密度，使其接近单晶的相应值，同时不会损失孔隙率，从而提高了体积储氢容量，接近单晶的上限。高体积吸氢量与低且恒定的吸附热相结合，假设在77 K - 100 bar和117 K - 5 bar之间进行变温变压吸附过程，每升颗粒可提供约31 g可用氢气。循环实验未表明储氢容量有任何下降。ZIF-8颗粒在制备、处理和操作过程中表现出的出色稳定性证明了其作为一种坚固吸附材料在中试和全尺寸吸附容器原型技术应用中的潜力。
