Search

CoMo/Al2O3-ASA catalysts with different Al2O3/ASA ratio have been studied. The amount of ASA (Si/Al ratio 0.25 wt./wt.) varied from 0 to 100 % in the support. Supports and catalysts were characterized by low-temperature N2 adsorption-desorption, TPD-NH3, IRS of adsorbed pyridine, HRTEM, UV-vis spectroscopy, XPS, XRD, bulk crushing strength. Catalysts were tested in hydrotreating of the model FCC gasoline containing 250 ppm of sulfur from thiophene, 40 wt.% of toluene, 40 wt.% of heptane and 20 wt.% of 1-hexene. It was shown that the introduction of ASA to the support increased the amount of weak Brønsted acid sites and weak and medium Lewis acid sites. The addition of ASA changed the morphology of sulfide active component and extract Co from the composition of the CoMoS phase. It was shown that presence of more than 50 wt.% of ASA in the samples demonstrated significant changes in the selectivity of CoMo catalysts.

Amorphous carbon (AC) is present in the bulk and on the surface of nanostructured carbon materials (NCMs) and exerts a significant effect on the physical, chemical and mechanical properties of NCMs. Thus, the determination of AC in NCMs is extremely important for controlling the properties of a wide range of materials. In this work, a comparative study of the effect of heat treatment on the structure and content of amorphous carbon in deposited AC film, nanodiamonds, carbon black and multiwalled carbon nanotube samples was carried out by TEM, XPS, XRD and Raman spectroscopy. It has been established that the use of the 7-peak model for fitting the Raman spectra makes it possible not only to isolate the contribution of the modes of amorphous carbon but also to improve the accuracy of fitting the fundamental G and D2 (D) modes and obtain a satisfactory convergence between XPS and Raman spectroscopy. The use of this model for fitting the Raman spectra of deposited AC film, ND, CB and MWCNT films demonstrated its validity and effectiveness for investigating the amorphous carbon in various carbon systems and its applicability in comparative studies of other NCMs.

The morphology, chemical composition, and electronic properties of Al2O3/InGaAs interfaces with and without anodic oxide layers, formed in DC plasma (O2, Ar) with different contents of the fluorinating component (CF4), were studied. It is shown that thin fluorinated anodic oxide layers, in combination with annealing at 300 °C, reduce the density of interface states by a factor of 3–4 over the entire bandgap. The minimum state density values near the midgap determined by the Terman method are about 2 × 1012 eV−1 cm−2. However, it is demonstrated that, in contrast to the Al2O3/InGaAs interface, the interface with a fluorinated oxide is not stable and degrades when heated above 300 °C.