Effect of the ruthenium deposition method on the nanostructured catalyst activity in the deep hydrogenation of benzene

Ru-containing catalysts supported on halloysite aluminosilicate nanotubes (HNTs) were prepared by incipient wetness impregnation, vacuum impregnation, and impregnation under the microwave irradiation methods. Composition and structure of the catalysts were determined by X-ray fluorescence (XRF), thermo-programmed reduction (TPR-H2), and transmission electron microscopy (TEM). Textural characteristics were detected by low-temperature nitrogen adsorption—desorption. The activity of the catalysts was investigated in benzene hydrogenation at 80°?, a hydrogen pressure of 3.0 MPa, and a molar ratio of benzene to Ru of 2000. It was found that Ru nanoparticles prepared by vacuum impregnation are deposited mainly into the internal cavity of aluminosilicate nanotubes, while in samples obtained by wetness impregnation the active phase is formed predominantly on the external surface of halloysite. The catalyst prepared by impregnation under microwave irradiation is characterized by a high Ru content, its uniformly distributed metal particles are located mainly on the external surface of HNT, and it demonstrated the superior activity in hydrogenation of benzene to cyclohexane.