V. I. Isaeva

Metal-organic frameworks—New materials for hydrogen storage

Published data on the physical sorption of hydrogen by new materials with a large specific surface area, crystalline microporous metal-organic frameworks (MOFs), are systematized and analyzed. The hydrogen-accumulating properties of MOFs are compared with those of traditional materials (charcoals and zeolites) and nanocarbon systems. The role of secondary hydrogen spillover in the development of new approaches to increase the adsorption capacity of hydrogen storage materials is separately considered.

In situ synthesis of novel ZIF-8 membranes on polymeric and inorganic supports

The fabrication of integrated ZIF-8 membranes via a direct in situ crystallization on a porous polyacrylonitrile material and a composite aluminum zirconate based support was performed for the first time. A novel free-seeding synthetic procedure was accomplished without an elevated temperature and autogeneous pressure. The proper choice of the support in combination with the appropriate synthesis procedure allowed for the preparation of phase-pure polycrystalline ZIF-8 membranes. The gas permeation experiments indicated that dense ZIF-8 selective layers, including a multi-layer coating, were perfectly grown on both the supports. Our results revealed a strong impact of the support on the gas separation characteristics of the resulting ZIF-8 membranes.

Platinum-containing catalyst supported on a metal-organic framework structure in the selective oxidation of benzyl alcohol derivatives into aldehydes

The platinum catalyst supported on the metal-organic framework structure MOF-5 is usable in the selective oxidation of vanillyl and piperonyl alcohols into the corresponding aldehydes.

Structure and catalytic activity of supported metal complexes. Communication 2. Synthesis of rhodium complexes on silica gel modified by phosphorus- and nitrogen-containing ligands

Conclusions1.Silica gel has been modified by aminophosphine groups and rhodium complexes immobilized on it: [RhCl(COD)]2, RhCl(PPh3)3, and RhCl3. IR spectroscopy was used to follow the formation of aminophosphine groups on the surface of the silica gel as the γ-aminopropyl silica reacted with the Ph2PCl.2.Using IR spectroscopy and GLC it has been shown that bonding of [RhCl(COD)]2 on a γ-aminopropyl-containing silica gel proceeds without replacement, while on the γ-aminophosphino-propyl-containing silica gel, the cyclooctadiene ligand is replaced. When complexes become bound to the latter support, the rhodium atom coordinates through the phosphorus atom of the aminophosphine group; the extent to which the nitrogen participates depends on the identity of the type of compounds immobilized.3.The activity and selectivity exhibited by the catalysts obtained in the conversion of the allylbenzene depends on the nature of the bonded ligand and the starting complex, the degree of ligand exchange, and the properties of the solvent.

Study of selective adsorption of aromatic compounds from solutions by the flexible MIL-53(Al) metal-organic framework

The dynamic method under conditions close to equilibrium was applied to study the liquid-phase adsorption in the Henry region for a series of aromatic compounds on the MIL-53(Al) metal-organic framework at different temperatures. The interpretation of the obtained experimental adsorption data was based on the TOPOS analysis of the structure of the cavities in the MIL-53(Al) framework using the Voronoi—Dirichlet polyhedra concept. It is shown that the adsorption activity of the investigated material under the liquid-phase conditions is governed by a possible expansion of the channels and cavities in the structure and by a breathing effect of the structure caused by the temperature variation. The selectivity of adsorption shown by MIL-53(Al) for a series of the studied compounds is due to the adsorbate—adsorbent π—π-interaction and hydrogen bonding of adsorbate molecules with Brönsted acid sites of the metal-organic framework. High adsorption selectivity of the MIL-53(Al) framework were found for compounds differed in the number of aromatic rings in the molecule and the presence of the methyl substituent, as well as for aromatic hydrocarbons and their sulfur-containing heterocyclic analogs.

Hydrogenation of α-oxophosphonates with molecular hydrogen catalyzed by palladium on carbon carrier as synthesis procedure for α-hydroxyphosphonates

Hydrogenation with molecular hydrogen of substituted benzoylphosphonic acids ethyl esters provides a convenient preparation method for diethyl [hydroxy(aryl)methyl]phosphonates. Both the palladium on activated carbon and the palladium immobilized in a chitosan matrix applied on a carbon carrier sibunit can be employed as catalysts.

Novel catalysts for selective hydrogenation of C≡C bond based on Pd nanoparticles immobilized in phenylenecarboxylate frameworks (NH2)-MIL-53(Al)

Novel catalysts based on Pd nanoparticles encapsulated into microporous metal-organic framework MIL-53(Al) and NH2-MIL-53(Al) were synthesized. Their catalytic properties were studied in the model reaction of liquid-phase hydrogenation of diphenylacetylene (DPA) (293 K,

1,3-Cyclohexadiene hydrogenation in the presence of a palladium-containing catalytic system based on an MOF-5/calixarene composite

P_{H_2 }