Theoretical modeling of the interaction of phenylacetylene and styrene molecules with Pd{111}

The DFT-PBE method was used to calculate the structural and energy characteristics of all possible adsorption complexes of phenylacetylene (PA) and styrene (St) molecules with the Pd{111} surface. According to the calculations, the acetylene group of the PA molecule in the energetically preferred complexes is bound to three or four Pd atoms and the plane of the phenyl ring is parallel to the Pd surface. In the case of deficiency of fcc sites, the phenyl ring of the PA molecule is displaced from the Pd{111} surface. The number of Pd atoms required for the compact adsorption of two PA molecules is the same as that for the adsorption of one St molecule.     

Metallopolymer nanocomposites based on platinum nanoparticles for chemical fuel cells

Platinum nanoparticles were synthesized by radiation chemical reduction in solutions of reverse micelles for the modification of Nafion films. The effect of the degree of solubilization and sizes of water pools of micelles on nanoparticle formation was shown. The platinum nanoparticle size in the polymer matrix does not exceed 10 nm.     

Study of alkene epoxidation in the presence of extruded silicalite titanium

Main features of liquid-phase epoxidation of propylene, allyl chloride, and allyl alcohol by aqueous solution of hydrogen peroxide in the presence of extruded titanium silicalite in methanol medium have been investigated. The effects of the solvent, the initial ratio of the organic substrate: hydrogen peroxide, and temperature on the yield of main products and by-products were elucidated. Based on the obtained features the conditions for the synthesis of propylene oxide, epichlorohydrin, and glycidol in a laboratory continuous set-up were established.     

Unconventional Allylation of Norbornadiene Catalyzed by Palladium Complexes

A new catalytic system based on palladium complex compounds for the unconventional allylation of norbornadiene with allylic esters of carboxylic acids is developed. The structure of reaction products is determined and the factors affecting their ratio are found. Comparative analysis of the palladium and nickel catalytic systems is performed.     

Synthesis and properties of the ordered structures of polymer microspheres

Russian Chemical Bulletin - Ordered structures of polymer microspheres of various diameters (6–200 μm) were prepared on a water surface followed by transposition and fixation on a solid...     

Synthesis and catalytic activity of platinum/porous silicon nanocomposites

Physicochemical characteristics of the functional electrode nanocomposites based on porous silicon with platinum nanoparticles were investigated with the use of electron microscopy, X-ray diffraction, and cyclic voltammetry. It is established that a decrease in the platinum nanoparticle size leads to an increase in catalytic activity of nanocomposites in the reactions of electrocatalytic oxygen reduction and hydrogen oxidation.     

Hydride transfer mechanism in the catalytic allylation of norbornadiene with allyl formate

Russian Chemical Bulletin - Allylation of norbornadiene with allyl formate in the presence of the palladium catalytic systems is characterized by several peculiarities associated with the new...     

Codimerization of norbornene and 1,3-cyclopentadiene: quantum chemical and experimental research

A comprehensive theoretical and experimental research of the diene synthesis involving norbornene (1) and 1,3-cyclopentadiene (2) was carried out. The thermodynamic and kinetic parameters were evaluated by quantum chemical methods, and the structures of stereoisomeric products and the quantitative estimation of their ratio were predicted. The results of quantum chemical analysis were experimentally confirmed. The structures of codimers of 1 with 2 and their ratio were determined by a number of physicochemical methods. A strategy combining the theoretical and experimental studies and enabling to optimize the search for objects for the synthesis and reaction conditions was proposed.     

Catalysts with platinum–palladium nanoparticles on polymer matrix supports

The platinum–palladium/Nafion metal–polymer nanocomposites were synthesized by the chemical reduction of ions in the aqueous organic solutions of inverted microemulsions. The functional characteristics of the nanocomposites were studied by cyclic voltammetry, atomic force microscopy, and scanning electron microscopy. The nanocatalysts obtained exhibited high activity in the reactions of oxygen reduction and hydrogen oxidation. The influence of synthesis conditions on the catalytic activity of the metal–polymer nanocomposites was studied.     

Regularities of formic acid oxidation in the presence of porous silicon nanocomposites with palladium

Nanocomposites demonstrating high catalytic activity in the oxidation of formic acid were obtained by depositing palladium on porous silicon support. The palladium samples on porous silicon are superior to commercial samples on carbon black in many characteristics. A decrease in the size of palladium nanoparticles favors an increase in the catalytic activity of the palladium/porous silicon nanocomposites.