The influence of the lanthanide cation type on the structure and catalytic properties of Ln zirconates (Ln = La – Lu) obtained by coprecipitation was studied. It was found that Ln (La, Pr – Lu) zirconates are single-phase and have a face-centered cubic structure of a defect fluorite (sp. gr. \(Fm\bar{3}m\) (225)) with nonequivalent positions of the \(Ln^{3+}\) and \({\text {Zr}^{4+}}\) cations. Ce zirconate was a mixture of cubic \({\text {CeO}_2}\) (sp. gr. \(Fm\bar{3}m\) ) and tetragonal \({(\text {Zr}_{0.9}\text {Ce}_{0.1})\text {O}_2}\) (sp. gr. \(P4_2/nmc\) (137)). A study of the local structure showed possible formation of nanodomains with pyrochlore ordering in the fluorite matrix for light Ln zirconates. For heavy Ln zirconates, the emergence of \(\delta\) -phase nanodomains in the fluorite matrix is revealed. The use of Ln zirconates significantly reduces the onset temperature of propane conversion and increases its conversion degree. It was established that the ionic radius and electron structure of the \(Ln^{3+}\) cation determine the acidity of the active sites and the energy characteristics (i.e., adsorption energy and differential heat of adsorption), which are the main factors determining the adsorption capacity and pathways of the propane conversion process. The use of light Ln zirconates with the maximum concentration of Lewis acid sites facilitates the propane dehydrogenation reaction to form propylene. A decrease in the number of Lewis acid sites and an increase in the number of Brønsted acid sites as the 4f shell of the \(Ln^{3+}\) cations gets progressively filled facilitates the propane cracking reaction to form a mixture of methane, ethylene, and ethane. Hourly screening showed that an increase in the operation time beyond 7 h leads to a significant change in the catalytic properties due to coking of the active catalytic sites.
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