The CO ₂ -assisted oxidative dehydrogenation of ethane (ODH-CO ₂ ) attracts a lot of research interest since it combines greenhouse gas utilization with the production of valuable chemicals.

Using XRD, ²⁷Al and ³¹P MAS NMR, Raman spectroscopy, SEM, TEM, N₂ adsorption–desorption, and IR spectroscopy with pyridine adsorption, we studied the influence of the aluminum source and the aging temperature of the gel with the following composition: 1.0Al₂O₃·1.0P₂O₅·0.2SiO₂·1.5DPA·30H₂O, on the properties of the formed intermediate phases and the products of their subsequent crystallization in SAPO-11 molecular sieves. It has been established that by changing the nature of the aluminum source and the gel aging temperature, it is possible to synthesize various intermediate silicoaluminophosphates (amorphous, layered, AlPO₄·2H₂O) and control the morphology and size of the crystals formed during further crystallization of the SAPO-11 molecular sieves. The high stability and selectivity of the synthesized SAPO-11 nanoscale sample in the reaction of vapor-phase isomerization of cyclohexanone oxime to caprolactam were shown.

The physicochemical properties of a series of catalysts based on granulated Na-Yh zeolite with the hierarchic (micro–meso–macro) pore structure (Na-Yh, HNa-Yh, MgO/Na-Yh, La₂O₃/Na-Yh, TiO₂/Na-Yh) and the activity and selectivity of these catalysts in isophorone aromatization were studied. MgO/Na-Yh and La₂O₃/Na-Yh zeolites with high content of basic sites and low content of Brønsted acid sites are the most effective in the synthesis of 3,5-dimethylphenol: The 3,5-dimethylphenol formation selectivity reaches 63–69% at 87–94% isophorone conversion. In the presence of Na-Yh zeolite containing both acid and base sites, the prevalent reactions are isophorone isomerization and synthesis of trimethylbenzenes. The modification of Na-Yh with titanium oxide leads to an increase in the content of acid sites on the TiO₂/Na-Yh surface and to the prevalence of the aromatization to form trimethylbenzenes. In the presence of HNa-Yh containing a set of the strongest Brønsted and Lewis acid sites, isophorone transforms into a mixture of polymethylbenzenes.

A new approach to the synthesis of a nanosized and hierarchical titanosilicate, TS-1, is presented. Instead of using specific solid or additional mesoporous templates or individual additives to slow down the hydrolysis of titanium alkoxides, it is proposed that the titanosilicate TS-1 can be obtained from gels synthesized with hydrolysis catalysts (HNO₃ and tetrapropylammonium hydroxide). When nitric acid catalyzes tetraethyl orthosilicate (TEOS) hydrolysis, the resulting crystalline TS-1 that can be obtained has uniform particle sizes (150–180 nm), is anatase-free, and contains up to 46–67% of mesopores. When a base catalyst is applied, the obtained material’s features are opposite. Moreover, acid-promoted TS-1 samples catalyze cyclohexene H₂O₂-oxidation via a heterolytic route to the cyclohexane epoxide with 67% selectivity, which is non-typical.

Amorphous mesoporous materials are promising as catalysts for processes involving or forming bulk molecules. In a reaction such as acetone condensation to form mesitylene, an effective catalyst should not only have a developed porous structure but also have active centers of acidic and basic types. The sol–gel approach allows one to obtain titanosilicates with such characteristics. This work demonstrates the possibility of controlling their properties by varying the conditions for the synthesis of titanosilicate gels. It has been established that controlling hydrolysis allows one to increase the activity of amorphous mesoporous titanosilicates by 10 times: from acetone conversion of 6% to 60%. It has been shown that the use of titanium acetylacetonate complexes in the synthesis of gels leads to an increase in the content of tetracoordinated Ti in the structure and contributes to an increase in the acidity of titanosilicates. During the condensation of acetone on the obtained mesoporous titanosilicates, high acetone conversion (60–79%) and mesitylene selectivity of up to 83% were achieved.