Angélique Simon-Masseron

Adsorption of CO2, CH4, and N2 on Zeolitic Imidazolate Frameworks: Experiments and Simulations

Experimental measurements and molecular simulations were conducted for two zeolitic imidazolate frameworks, ZIF-8 and ZIF-76. The transferability of the force field was tested by comparing molecular simulation results of gas adsorption with experimental data available in the literature for other ZIF materials (ZIF-69). Owing to the good agreement observed between simulation and experimental data, the simulation results can be used to identify preferential adsorption sites, which are located close to the organic linkers. Topological mapping of the potential-energy surfaces makes it possible to relate the preferential adsorption sites, Henry constant, and isosteric heats of adsorption at zero coverage to the nature of the host-guest interactions and the chemical nature of the organic linker. The role played by the topology of the solid and the organic linkers, instead of the metal sites, upon gas adsorption on zeolite-like metal-organic frameworks is discussed.

Comparison of the Behavior of Metal–Organic Frameworks and Zeolites for Hydrocarbon Separations

The objective of this work was to study the adsorption and separation of the most important families of hydrocarbon compounds on metal-organic frameworks (MOFs), in comparison with zeolites. For this purpose, we have selected four probe molecules, each of them representing one of these families, i.e., o- and p-xylene as aromatics, 1-octene as an alkene, and n-octane as an alkane. The separation of these four molecules was studied by binary breakthrough experiments. To represent the large diversity of MOF structures, the experiments were carried out with (i) two MOFs with coordinatively unsaturated metal sites (CUS), i.e., Cu-btc (HKUST-1) and CPO-27-Ni, (ii) a MOF with an anionic framework and extraframework cations, i.e. RHO-ZMOF, and (iii) two rather apolar zeolitic imidazolate framework (ZIF) materials with different pore sizes, i.e. ZIF-8 and ZIF-76. Zeolite NaY and zeolite β were used as polar and apolar reference adsorbents, respectively. The results can be briefly summarized as follows: ZIFs (not carrying any polar functional groups) behave like apolar adsorbents and exhibit very interesting and unexpected molecular sieving properties. CUS-MOFs behave like polar adsorbents but show the specificity of preferring alkenes over aromatics. This feature is rationalized thanks to DFT+D calculations. MOFs with extraframework cations behave like polar (cationic) zeolites.

IM-19: a new flexible microporous gallium based-MOF framework with pressure- and temperature-dependent openings.

Five metal-organic frameworks (MOFs) based on the same three-dimensional gallium terephthalate network (IM-19) are described, and an incommensurate structure (for the as-synthesized form) as well as two remarkable guest-free polymorphs (open and closed) are highlighted.

Hydrothermal Synthesis and Characterization of the New Layered Fluorogallophosphate Mu‐23

Mu-23, [(C(6)H(15)N(2))(C(6)H(16)N(2))Ga(5)F(6)(H(2)O)(2)(PO(4))(4)] x 4 H(2)O, the first layered fluorinated gallophosphate with a Ga/P molar ratio of 5:4, was obtained in the presence of fluoride ions with 1,4-dimethylpiperazine as an organic template. It crystallizes in the triclinic space group P1 (no. 2) with unit cell parameters a=8.735(11), b=8.864(5), c=12.636(10) A, alpha=98.36(5), beta=100.18(8), gamma=115.84(7) degrees. The layers consist of GaO(2)F(3)(H(2)O), GaO(4)F(2) octahedra, and GaO(4) and PO(4) tetrahedra; these moieties share their oxygen and some of their fluorine atoms. The connectivity scheme of these different polyhedra leads to the formation of eight-membered rings.

Solvothermal Synthesis, Structure, Fluorescence and Magnetism Properties of a Novel 3D Metal-Organic Framework Based on Tetranuclear Copper Secondary Building Units

A novel 3D metal-organic framework based on tetranuclear copper Secondary Building Units, [Cu2(μ3-OH)(4-oip)(DMF)]·DMF·2H2O (JUC-76) (4-oip = 4-hydroxyisophthalic, DMF = N,N-dimethylformamide, and JUC = Jilin University China), has been synthesized under solvothermal conditions. It crystallizes in monoclinic symmetry with space group P21/n. JUC-76 possesses a three-dimensional network with one-dimensional rhombic channels of approximately 13.6 × 8.5 Å2 along the [100] direction. The resulting structure of JUC-76 is a distorted rutile topology with one 3-connected organic node and one 6-connected inorganic node. And its Schläfli symbol is (4·62)2(42·610·83). In addition, JUC-76 exhibits fluorescence emission at 446 nm, and a dominant anti-ferromagnetic interaction between the Cu (II) ions.

Experimental study of the zeolite affinity for the dioxin adsorption for a new direct and on-line measurement method

Dioxins are toxic and ubiquitous compounds that are unintentional by-products of combustion processes. Because of their health effects, a number of countries have introduced stringent emission standards. Current and standard methods used to determine the emissions of dioxins, from an incinerator for example, do not allow to know and control the concentration of dioxins in “real time”. The present work describes the first steps of the development of a new experimental methodology for on-line and direct monitoring of gas phase dioxin traces emitted by municipal solid waste incinerators.

Synthesis route of microporous metallophosphates by in situ generation of the structure directing agent: the gallophosphate Ea-TREN GaPO

This work focuses on the synthesis of microporous materials by a new synthesis route developed in the phosphate-based system (aluminophosphates, gallophosphates, etc.). It consists in the in situ generation of the structure-directing agent (SDA) from alkylformamides. These molecules decompose into alkylamines and the in situ release of the amine during the synthesis appears to be a key step in the crystallization of the phosphate- based materials. Indeed, experiments performed directly in the presence of alkylamine in the starting mixture did not lead to the crystallization of the same materials.

Hydrothermal synthesis and characterization of new phosphate-based materials prepared in the presence of 1,4-dimethylpiperazine

Two new phosphate-based materials, Mu-23 and Mu-25, are prepared with 1,4-dimethylpiperazine as structure directing agent. Mu-23 is the first two-dimensional fluorinated gallophosphate with a Ga/P molar ratio of 5/4. This new phosphate-based material, with the chemical formula [(C 6 H 15 N 2 )(C 6 H 16 N 2 )Ga 5 F 6 (H 2 O) 2 (PO 4 ) 4 ]⊙4H 2 O, crystallizes in the triclinic space group P-1 with the following unit cell parameters: a=8.735(11) , b=8.864(5) , c=12.636(10) , α=98.36(5)°, β=100.18(8)°, γ=115.84(7)°. The symmetry of the three-dimensional zincophosphate Mu-25, [(C 6 H 16 N 2 )Zn 2 (HPO 4 ) 3 ], is monoclinic (space group P 2 1 /n) with a=8.641(5) , b=14.364(9) , c=12.581(11) , β=96.39(6)°. The layers of the gallophosphate consist of GaO 2 F 3 (H 2 O), GaO 4 F 2 octahedra and GaO 4 , PO 4 tetrahedra which share their oxygen and some of their fluorine atoms. The connectivity scheme of these different polyhedra leads to the formation of 8-membered rings. The framework of Mu-25 results from tetrahedrally coordinated zinc and pphosphorus atoms linked through oxygen vertices. The interrupted framework (presence of P-OH and P=O bondings) displays channels with 4-, 8- and 12-membered ring openings. Structures were determined by single crystal X-ray diffraction and characterized by Solid State NMR spectroscopy, thermogravimetric (TGA) and differential thermal (DTA) analyses.