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1.The number and activity of the oxidative centers in H-mordenite depend on the conditions of preliminary heat treatment. At low temperatures of heating (150–200°C) in the presence of O2, H-mordenite already acquires the ability to adsorb hydrocarbons with the formation of cation radicals.2.Decationized mordenites with a degree of substitution of Na+ ions for H+ less than 50% are inactive in the formation of cation radicals.3.On the basis of the data obtained and an analysis of the interatomic distances in the structure of mordenite, it was hypothesized that during the process of its heat treatment in the presence of O2, together with the centers including Al3+ ions, centers $$\begin{array}{*{20}c} \backslash \\ - \\ / \\ \end{array} Si - O^. $$ , active in the formation of cations radicals of benzene, arise.

1.The activity of catalysts containing 2 and 20% NiO on SiO2-Al2O3 in dimerization reactions of ethylene depends on the Al2O3 content.2.The degree of oligomerization of isobutylene and double-bond migration in n-butenes, formed by ethylene dimerization, changes in agreement with the total acidity of the catalyst on 2% NiO-SiO2-Al2O3 catalyst.

1.The catalyst NiO-SiO2 acquires activity in the reaction of dimerization of C2H4 when Al2O3 is introduced into it.2.With increasing Al2O3 content in the catalyst, the conversion of C2H4 and i-C4H8 and the number of electron acceptor centers, recordable by ESR, pass through a maximum (1–3% Al), while the total acidity of the catalyst increases.

1.The method of photoelectron spectroscopy has been used to show that the Co and Mo ions of CoO-MoO3-Al2O3 catalysts interact with the ?-Al2O3 lattice, the Mo ions blocking the penetration of the Co ions. Formation of metallic Co promotes extensive Mo ion reduction.2.Thermal treatment of the CoO-MoO3-Al2O3 catalyst in air tends to enrich the surface with respect to Mo ions, while reduction enriches the surface with respect to Co ions.3.Oxidational treatment of the CoO-MoO3-Al2O3 and MoO3-Al2O3 catalysts is required for formation of anthracene radical-cations. A description is given of an oxidizing center structure which accounts for the reduction in acceptor activity of the Mo6+ ions in the ternary system.

Conclusions When the amount of aluminum in a nickel-containing mordenite with variable degree of dealuminization is increased the total acidity of the zeolite increases, the concentration of the electron-acceptor centers, recorded by the EPR method, passes through a maximum, while the degree of ethylene conversion varies within narrow limits.