Adsorbent-based hydrogen storage systems offer a potential solution to current challenges in hydrogen storage, particularly those requiring high pressures or cryogenic temperatures. Specifically, the use of metal–organic frameworks (MOFs) featuring open metal sites that strongly adsorb hydrogen represents a promising strategy for near-ambient-temperature hydrogen storage. This study investigates the hydrogen storage properties of M2(dondc) (M = Mg2+, Co2+, and Ni2+), an extended version of MOF-74. Among this series, Ni2(dondc) exhibits the second-highest volumetric hydrogen capacity of 10.74 g L−1 at 298 K under pressure swing adsorption conditions (100 to 5 bar) at ambient temperatures. The superior hydrogen storage performance of Ni2(dondc) is attributed to its highly polarizable Ni open metal sites and a significant heat of adsorption of 12.2 kJ mol−1. These findings are corroborated by temperature-programmed desorption spectroscopy and van der Waals-corrected density functional theory calculations. In addition to its exceptional hydrogen capacity, Ni2(dondc) exhibits robust structural stability and long-term durability, positioning it as a promising candidate for near-ambient-temperature hydrogen storage applications.

中文翻译：

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经过微调的 MOF-74 型变体，具有开放式金属位点，可在接近环境温度下进行高容量储氢


基于吸附剂的储氢系统为当前储氢挑战提供了潜在的解决方案，特别是那些需要高压或低温的储氢挑战。具体来说，使用具有强烈吸附氢的开放金属位点的金属有机框架（MOF）代表了一种有前景的近环境温度储氢策略。本研究研究了 MOF-74 的扩展版本 M2(dondc)（M = Mg2+、Co2+ 和 Ni2+）的储氢特性。在该系列中，Ni2(dondc) 在环境温度下的变压吸附条件（100 至 5 bar）下，在 298 K 下表现出第二高的体积氢容量，为 10.74 g L−1。 Ni2(dondc) 优异的储氢性能归因于其高度极化的 Ni 开放金属位点和 12.2 kJ mol−1 的显着吸附热。这些发现得到了程序升温解吸光谱和范德华校正密度泛函理论计算的证实。除了其卓越的氢容量外，Ni2(dondc)还表现出强大的结构稳定性和长期耐用性，使其成为近环境温度储氢应用的有前途的候选者。