Abstract
Nickel and molybdenum oxide catalysts synthesized using cation- and anion-modified alumina as a support (Na2O–Al2O3, MgO–Al2O3, Al2O3–Al2O3, ZrO2–Al2O3, B2O3–Al2O3, \({\text{SO}}_{4}^{{2 - }}\) –Al2O3) were studied. Data on the effect of support surface modification on the physicochemical properties and activity of the catalysts in ethylene conversion to propylene were obtained. It was shown that anionic modification (B2O3–Al2O3, \({\text{SO}}_{4}^{{2 - }}\) –Al2O3) improves catalyst activity catalyst activity due to the formation of octahedrally coordinated Ni2+ cations bound to the surface acid sites of the support. Cationic modification (Na2O–Al2O3, MgO–Al2O3, Al2O3–Al2O3, ZrO2–Al2O3), conversely, suppresses the development of ethylene conversion reactions due to a lower content of medium-strength and strong acid sites, which determine the strength of interaction with nickel cations, on the surface of these supports. The maximum propylene yield of 51–52 wt % is provided by catalysts based on a borate-containing support and unmodified alumina. They are characterized by the presence of highly dispersed species of polymolybdate compounds and medium-strength Brønsted acid sites on their surface.
