英国曼彻斯特大学杨四海、Martin Schröder团队揭示了高氨吸附MFM300材料中主客体结合的动力学和电荷转移机制。 相关研究成果于2021年2月19日发表在国际知名学术期刊《美国化学会杂志》。

氨（NH3）因其高氢密度而成为一种很有前途的能源。然而，由于缺乏高效耐腐蚀的储存材料，限制了其广泛应用。

该文中，研究人员报道了一系列坚固的金属有机骨架（MOF）材料MFM-300（M）（M=Fe，V，Cr，In），对NH3具有高吸附。MFM-300(M) (M = Fe, V^III, Cr)，在273 K和1 bar的条件下，容量分别达到16.1,15.6和14.0 mmol g^-1，显示出>20次的循环存储。在相同条件下，MFM-300（V^IV）在这一系列MOFs中表现出最高的摄取量，为17.3mmol g^–1。原位中子粉末衍射、单晶X射线衍射和电子顺磁共振谱证实，氧化还原活性V中心使主-客体电荷转移，V^IV被还原为V^III，NH3被氧化为肼（N2H4）。

原位非弹性中子散射和DFT模型相结合，揭示了吸附态NH3在MOFs中的结合动力学，为MOF材料在NH3吸附转化中的应用提供了全面的认识。

附：英文原文

Title: High Ammonia Adsorption in MFM-300 Materials: Dynamics and Charge Transfer in Host–Guest Binding

Author: Xue Han, Wanpeng Lu, Yinlin Chen, Ivan da Silva, Jiangnan Li, Longfei Lin, Weiyao Li, Alena M. Sheveleva, Harry G. W. Godfrey, Zhenzhong Lu, Floriana Tuna, Eric J. L. McInnes, Yongqiang Cheng, Luke L. Daemen, Laura J. McCormick McPherson, Simon J. Teat, Mark D. Frogley, Svemir Rudi, Pascal Manuel, Anibal J. Ramirez-Cuesta, Sihai Yang, Martin Schrder

Issue&Volume: February 19, 2021

Abstract: Ammonia (NH3) is a promising energy resource owing to its high hydrogen density. However, its widespread application is restricted by the lack of efficient and corrosion-resistant storage materials. Here, we report high NH3 adsorption in a series of robust metal–organic framework (MOF) materials, MFM-300(M) (M = Fe, V, Cr, In). MFM-300(M) (M = Fe, VIII, Cr) show fully reversible capacity for >20 cycles, reaching capacities of 16.1, 15.6, and 14.0 mmol g–1, respectively, at 273 K and 1 bar. Under the same conditions, MFM-300(VIV) exhibits the highest uptake among this series of MOFs of 17.3 mmol g–1. In situ neutron powder diffraction, single-crystal X-ray diffraction, and electron paramagnetic resonance spectroscopy confirm that the redox-active V center enables host–guest charge transfer, with VIV being reduced to VIII and NH3 being oxidized to hydrazine (N2H4). A combination of in situ inelastic neutron scattering and DFT modeling has revealed the binding dynamics of adsorbed NH3 within these MOFs to afford a comprehensive insight into the application of MOF materials to the adsorption and conversion of NH3.

DOI: 10.1021/jacs.0c11930

Source: https://pubs.acs.org/doi/10.1021/jacs.0c11930