• Li, Jiangnan
• Daemen, Luke L.
• Manuel, Pascal
• Lin, Longfei
• Frogley, Mark D.
• Tuna, Floriana
• Li, Weiyao
• Ramirez-Cuesta, Anibal J.
• Cheng, Yongqiang
• Lu, Wanpeng
• Godfrey, Harry G. W.
• Yang, Sihai
• Rudić, Svemir
• Chen, Yinlin
• Han, Xue
• Teat, Simon J.
• Schroder, Martin
• Lu, Zhenzhong
• Silva, Ivan Da
• Mpherson, Laura J. Mccormick
• Sheveleva, Alena M.
• Mcinnes, Eric J. L.

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.

Topics

• density
• impedance spectroscopy
• corrosion
• x-ray diffraction
• Hydrogen
• density functional theory
• electron spin resonance spectroscopy
• Inelastic neutron scattering
• magnetic force microscope