Chemistry Department, NIS, Centre of Excellence and INSTM Università di Torino, via Pietro Giuria 7 and via Quarello 11, 10100, Torino, Italy.
Dalton Trans. 2013 Sep 21;42(35):12586-95. doi: 10.1039/c3dt51312b.
Systematic studies of H2 adsorption by variable temperature infrared (VTIR) spectroscopy have added value in the characterization of hydrogen storage materials. As a key study to describe the potential of the method, here we report VTIR spectroscopy results of H2 adsorption at isostructural MOFs CPO-27-M (M = Mg, Mn, Co, Ni, Zn). The strongest perturbation of H2 vibrational frequency is due to the interaction with an open metal site. Although ionic radius is an empirical value, the direct correlation between ionic radii of the metal cation and H2 interaction energy is found in MOFs of the same topology. The highest enthalpy of hydrogen adsorption 15 ± 1 kJ mol(-1) was found for Ni(2+). VTIR results of H2 adsorption at isostructural MOFs CPO-27-M (M = Mg, Mn, Co, Ni, Zn) were compared with data obtained from analogous studies performed on a large variety of microporous materials (MOFs and zeolites), underlining the relevance of the approach to get reliable energetic and entropic (ΔH(0) and ΔS(0)) values to be compared with computational data and isosteric heats.
变温红外（VTIR）光谱法对 H2 吸附的系统研究在储氢材料的表征方面具有重要价值。作为描述该方法潜力的关键研究，本文报道了同构 MOF CPO-27-M（M=Mg、Mn、Co、Ni、Zn）中 H2 吸附的 VTIR 光谱结果。H2 振动频率的最强扰动归因于与开放金属位的相互作用。尽管离子半径是经验值，但在具有相同拓扑结构的 MOF 中发现了金属阳离子的离子半径与 H2 相互作用能之间的直接相关性。对于 Ni(2+)，发现了最高的 15±1kJ/mol 的氢吸附焓。同构 MOF CPO-27-M（M=Mg、Mn、Co、Ni、Zn）中 H2 吸附的 VTIR 结果与在各种微孔材料（MOF 和沸石）上进行的类似研究中获得的数据进行了比较，突出了该方法在获得可靠的能量和熵（ΔH(0)和ΔS(0)）值方面的相关性，以便与计算数据和等焓热进行比较。
