Observation of Binding and Rotation of Methane and Hydrogen within a Functional Metal–Organic Framework

Abstract

The key requirement for a portable store of natural gas is to maximize the amount of gas within the smallest possible space. The packing of methane (CH4) in a given storage medium at the highest possible density is, therefore, a highly desirable but challenging target. We report a microporous hydroxyl-decorated material, MFM-300(In) (MFM = Manchester Framework Material, replacing the NOTT designation), which displays a high volumetric uptake of 202 v/v at 298 K and 35 bar for CH4 and 488 v/v at 77 K and 20 bar for H2. Direct observation and quantification of the location, binding, and rotational modes of adsorbed CH4 and H2 molecules within this host have been achieved, using neutron diffraction and inelastic neutron scattering experiments, coupled with density functional theory (DFT) modeling. These complementary techniques reveal a very efficient packing of H2 and CH4 molecules within MFM-300(In), reminiscent of the condensed gas in pure component crystalline solids. We also report here, for the first time, the experimental observation of a direct binding interaction between adsorbed CH4 molecules and the hydroxyl groups within the pore of a material. This is different from the arrangement found in CH4/water clathrates, the CH4 store of nature.

Transistor‐Based Work‐Function Measurement of Metal–Organic Frameworks for Ultra‐Low‐Power, Rationally Designed Chemical Sensors

“…The MOF MFM-300(In) was prepared by as tandard method. [39] The crystals were dropcast over the surface of the device in acetone and activated in gentle heating. [40] Ad ropcast method was needed because at hin film could not be prepared on the device.…”

Structural and dynamic studies of substrate binding in porous metal–organic frameworks

“…The microporous hydroxy-decorated material, MFM-300(In) displays a high volumetric uptake of 202 v/v at 298 K and 35 bar for CH 4 and 488 v/v at 77 K and 20 bar for H 2 . 146 Direct observation and quantification of adsorbed H 2 and CH 4 molecules within MFM-300(In) have been achieved using a combination of NPD and INS techniques coupled with computational investigations. These complementary results suggest that the adsorbed CH 4 molecules form specific interactions with metal-bound hydroxy groups within the pore, supplemented by intermolecular dipole interactions between adsorbed CH 4 molecules and the phenyl-ring lined walls of the pore (Fig.…”

Selective Adsorption of Sulfur Dioxide in a Robust Metal–Organic Framework Material

“…Within the field of gas adsorption, major research interest has been focused on using MOFs for high capacity storage of hydrogen and methane, and for the separation of CO 2 and small molecule hydrocarbons. [9a,10,11] However, in contrast, studies on adsorption of SO 2 in MOFs have been very rarely reported due to the limited stability of coordination compounds to highly reactive SO 2 ; this is particularly the case for MOFs with open metal sites and this has precluded the study of adsorption of this important pollutant. Herein, we report the selective SO 2 adsorption in an ultra‐robust MOF material [MFM‐300(In)] with high adsorption capacity of SO 2 (8.28 mmol g −1 at 298 K and 1 bar) and, more importantly, exceptionally high selectivity of SO 2 /CO 2 (60), SO 2 /CH 4 (425), and SO 2 /N 2 (5000) under ambient conditions (i.e., 50:50 mixture at 1 bar and 298 K).…”

“…The complex MFM‐300(In) (MFM = Manchester Framework Material replacing the previous NOTT (Nottingham) designation) [In 2 (OH) 2 (L)] (H 4 L = biphenyl‐3,3′,5,5′‐tetracarboxylic acid) was synthesized by solvothermal reaction of In(NO 3 ) 3 and H 4 L in DMF ( N , N ‐dimethylformamide) at 90 °C . MFM‐300(In) is isostructural to MFM‐300(Al)[12a] and MFM‐300(Ga), and comprises chains of corner sharing [InO 4 (OH) 2 ] octahedra linked by mutually cis ‐μ 2 ‐OH groups, and further bridged by tetracarboxylate L 4− ligands.…”