A short review was given of the most important results of the theoretical and experimental studies at the Kinetics and Catalysis Laboratory, Department of Chemistry, Moscow State University, at the initial stage of the development of molecular sieve catalysis, when the procedure for the synthesis of crystalline aluminosilicates (zeolites) was developed and industrial-scale production of zeolites and zeolite-containing catalysts was launched. These results underlie further development of molecular sieve catalysis as a scientific basis for the production of Russian-made zeolites and catalysts for large-scale oil refining and petrochemical processes.

A short review was given of the most important results of the theoretical and experimental studies at the Kinetics and Catalysis Laboratory, Department of Chemistry, Moscow State University, at the initial stage of the development of molecular sieve catalysis, when the procedure for the synthesis of crystalline aluminosilicates (zeolites) was developed and industrial-scale production of zeolites and zeolite-containing catalysts was launched. These results underlie further development of molecular sieve catalysis as a scientific basis for the production of Russian-made zeolites and catalysts for large-scale oil refining and petrochemical processes.

Binary spinels of Со and Мn are obtained by means of hard-template synthesis. Their structural and chemical characteristics are determined via N 2 -BET, XRD, and TEM. Their catalytic activity is studied using methanol oxidation as the model reaction.

Structured mesoporous Mn, Fe, and Co oxides are synthesized using “soft” and “hard” templates; the resulting materials are characterized by XRD, SEM, TEM, BET, and TG. It is shown that in the first case, the oxides have high surface areas of up to 450 m 2 /g that are preserved after calcination of the material up to 300°C. Even though, the surface area of the oxides prepared by the “hard-template” method does not exceed 100 m 2 /g; it is, however, thermally stable up to 500°C. Catalytic activity of mesoporous oxides in methanol conversion was found to depend on both the nature of the transition metal and the type of template used in synthesis.

Tributylhexylammonium bistriflamide [(C4H9)(C6H13)N][(CF3SO2)2N], an ionic liquid, was used as a solvent for the Heck reaction of bromobenzene with styrene in the presence of Pd deposited onto a mesoporous carbon support. It was found that dibutylamine used as a basic reagent to scavenge hydrogen bromide results in higher conversions of the reactants and higher yields of stilbene than sodium acetate. It was shown that the IL is fully recoverable after use in the catalytic reaction.

The C-C cross coupling reaction between bromobenzene and styrene in the presence of Pd deposited on mesoporous acetylene soot (Pd/C) occurred in a tetraalkylammonium ionic liquid (IL) as a truly heterogeneous catalytic process. The active palladium form was not transferred into the reaction solution. Deposited palladium activation was observed when the Pd/C catalyst was preliminarily heated in the IL in the presence of dibutylamine as a base.

The catalytic properties of high-dispersity iron oxide deposited on micro-and mesoporous molecular sieves were studied. The deposition was performed by the in situ thermooxidative degradation of various precursors. The atomic catalytic activity of the catalysts in the oxidation of methanol was found to depend on both iron concentration and the accessibility of iron oxide particles.

Individual perovskite-like LaCoO3 obtained by the citrate method and LaCoO3 supported onto the mesoporous molecular sieve MSM-41 have been characterized by X-ray powder diffraction, EPMA, low-temperature nitrogen adsorption, H2 TPR, and EXAFS. The catalytic activity of the supported cobaltate in methanol oxidation is two orders of magnitude higher than the activity of the bulk cobaltate owing to nanosized LaCoO3 particles in the pores of the molecular sieve.

Rhenium and molybdenum oxide clusters were synthesized from the Re2O3(OMe)(6), ReMoO2(MeO)(7), and Mo2O2(OMe)(8) oxomethoxide complexes. The nanomaterials obtained were studied by the FTIR, DTA, EXAFS, and H-2-TPR techniques. It was established that, in microporous NaY zeolite, the oxomethoxide, complexes lose their ligands, so that only metal suboxide cores penetrate into the intracrystalline space, where they reside as nanosized clusters. It was found that the reduction of the clusters depends strongly on their size and the location in the matrix. The matrix environment also affects the transitions between different oxidation states of Re and Mo and the degree of reduction of their oxides.

The products of methanol conversion to hydrocarbons over a modified pentasil zeolite catalyst are classified by the Wojciechowski method of kinetic analysis as primary/secondary and stable/unstable. A general scheme of reaction pathways in methanol conversion to hydrocarbons over the pentasil-type zeolites is proposed.

The effect of the deposition of tetraphenylporphyrin (H2TPP) on silica gel on the size distribution of pores in it was studied. It was found that H2TPP molecules uniformly cover the carrier surface and retain their hydrophobic properties.

The mechanical destruction of catalyst granules, intensified by the action of environment, is the main cause of their losses in numerous heterogeneous catalytic processes. We developed a special complex of methods and devices for comprehensive quantitative investigations of the mechanical characteristics of catalyst and sorbent granules of any shape and size under various conditions of loading and wear, in particular, in the course of actual catalytic processes at the corresponding temperatures, including those used in oil cracking, ammonia synthesis, and the production of synthetic-caoutchouc monomers. Direct experiments with MgO, Co-Mo, Ca-Ni-P, Al-Cr-K, and other catalysts show that their strength and durability decrease significantly or even dramatically in the course of catalysis as compared with identical tests in an inert medium. This phenomenon is a result of the mutual influence of solid phase and environment: Due to the appearance of new bonds between them, the bonds both in adsorbed molecules and on the solid surface can weaken and rupture (i.e., the Rehbinder effects manifests itself here). From the thermodynamic viewpoint, this means that the work of an elementary catalytic event favors the mechanical disruption of an interatomic bond (several bonds) in the solid surface or even is sufficient for such a disruption. In this case, the catalyst under consideration becomes a victim of its destination. However, one can significantly enhance the wear resistance of catalyst granules by perfecting the entire technology of their production: selecting the optimal granulometric composition of particles that form granules, strengthening contacts between these particles with the use of fine inert fillers, applying the hydration hardening of mineral binders, reducing residual stresses, etc. The disruption of surface bonds caused by catalysis can also be accompanied by the appearance of new surface adatoms and, correspondingly, by the acceleration of surface self-diffusion and particle sintering, i.e., by an increase in strength or reaching the same level of development and strength of interparticle contacts at lower sintering temperatures (catalysis enhanced sintering). These effects were corroborated for both metals (Fe, Ni) and ceramic porous specimens (aluminum, zirconium, and yttrium oxides).

The effect of strengthening of pressed porous materials after the occurrence of catalytic reactions on them was shown to be characteristic not only of exothermic but also of endothermic processes. The observed effect was caused by the acceleration of surface diffusion of particles in the region of interparticle contacts as a result of conjugation of catalytic reactions with the formation of surface defects.