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

Abstract

NH3 (ammonia) 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, V III , 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 condition, MFM-300(V IV ) 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 centre enables host-guest charge-transfer, with V IV being reduced to V III and NH3 oxidised to hydrazine, N2H4. A combination of in situ inelastic neutron scattering and DFT modelling 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.

Dynamics & Spectroscopy with Neutrons—Recent Developments & Emerging Opportunities

“…Developments in gas-handling systems have also paved the way to probe gate-opening and related network-breathing phenomena arising from the unique elastic properties of MOFs—see entries in Table 1 and Refs. [ 151 , 266 , 267 , 268 , 269 , 270 , 271 , 272 , 273 , 274 , 275 , 276 , 277 , 278 , 279 , 280 , 281 , 282 , 283 , 284 , 285 , 286 , 287 , 288 , 289 , 290 ].…”

Reversible ammonia uptake at room temperature in a robust and tunable metal–organic framework

“…Metal–organic frameworks (MOFs) have emerged as a promising material for the capture of toxic chemicals such as NH 3 , 5–19 NO x , 20–23 SO x , 24–26 and volatile organic compounds 27,28 because well-ordered porosity with feasible chemical and structural tunability of pore surfaces enables such applications. Synthesis of MOFs with high structural stability toward corrosive species is a critical issue for real-world applications.…”

“…In this regard, several MOFs that can take up NH 3 under atmospheric condition has been developed recently. 5–19,29 Nevertheless, structural instability of adsorbent and high regeneration temperature are still remaining challenges for practical applications. 5,7–19 MOFs showing recyclable ammonia adsorption while retaining its porosity are still very rare.…”

“…5–19,29 Nevertheless, structural instability of adsorbent and high regeneration temperature are still remaining challenges for practical applications. 5,7–19 MOFs showing recyclable ammonia adsorption while retaining its porosity are still very rare. The limited stability of MOFs under ammonia conditions is ascribed to the coordinating nature of NH 3 .…”

Four Novel d10 Metal-Organic Frameworks Incorporating Amino-Functionalized Carboxylate Ligands: Synthesis, Structures, and Fluorescence Properties

“…(Barea et al, 2014;Canivet et al, 2014;Dhakshinamoorthy and Garcia, 2014;He et al, 2014;Hu et al, 2014;Liu et al, 2014;Van de Voorde et al, 2014;Silva et al, 2015;Zhu et al, 2015;Sheberla et al, 2017;Li et al, 2018;Park et al, 2018;Prasad et al, 2018;Wang et al, 2018;Cao et al, 2019;Mallick et al, 2019) For example, as a kind of new absorbent materials, quantities of MOFs have been widely investigated in the capture and separation of various gases, such as CO 2 , SO 2 , H 2 S, NH 3 , hydrocarbons and so on. (Li et al, 2009;Peng et al, 2013;Zhang et al, 2014;Trickett et al, 2017;Zárate et al, 2019a;Zárate et al, 2019b;Tchalala et al, 2019;Wang et al, 2020;Han et al, 2021) Varieties of MOFs have also been explored as luminescent materials in different fields, for example, sensing, nonlinear optical materials, OLED, and so forth. (Lustig et al, 2017;Medishetty et al, 2017;Gutiérrez et al, 2018) Although many MOFs have exhibited relatively superior performance, the majority of them do not meet the requirements of practical applications.…”