Современные концепции управления высшим учебным заведением

Целью и задачами статьи является исследование современных подходов к управлению вузом, их критический анализ и возможность оптимизации процессов деятельности вуза

Synthesis optimization of carbon-supported ZrO2 nanoparticles from different organometallic precursors

We report here the synthesis of carbon-supported ZrO2 nanoparticles from zirconium oxyphthalocyanine (ZrOPc) and acetylacetonate [Zr(acac)4]. Using thermogravimetric analysis (TGA) coupled with mass spectrometry (MS), we could investigate the thermal decomposition behavior of the chosen precursors. According to those results, we chose the heat treatment temperatures (THT) using partial oxidizing (PO) and reducing (RED) atmosphere. By X-ray diffraction we detected structure and size of the nanoparticles; the size was further confirmed by transmission electron microscopy. ZrO2 formation happens at lower temperature with Zr(acac)4 than with ZrOPc, due to the lower thermal stability and a higher oxygen amount in Zr(acac)4. Using ZrOPc at THT C900 °C, PO conditions facilitate the crystallite growth and formation of distinct tetragonal ZrO2, while with Zr(acac)4 a distinct tetragonal ZrO2 phase is observed already at THT C750 °C in both RED and PO conditions. Tuning of ZrO2 nanocrystallite size from 5 to 9 nm by varying the precursor loading is also demonstrated. The chemical state of zirconium was analyzed by X-ray photoelectron spectroscopy, which confirms ZrO2 formation from different synthesis routes

Physico-Chemical and Catalytic Properties of Mesoporous CuO-ZrO2 Catalysts

Mesoporous CuO-ZrO2 catalysts were prepared and calcined at 500 °C. The performance of the synthesized catalysts for benzylation of benzene using benzyl chloride was studied. The bare support (macroporous ZrO2) offered 45% benzyl chloride conversion after reaction time of 10 h at 75 °C. Significant increase in benzyl chloride conversion (98%) was observed after CuO loading (10 wt. %) on porous ZrO2 support. The conversion was decreased to 80% with increase of CuO loading to 20 wt. %. Different characterization techniques (XRD, Raman, diffuse reflectance UV-vis, N2-physisorption, H2-TPR, XPS and acidity measurements) were used to evaluate physico-chemical properties of CuO-ZrO2 catalysts; the results showed that the surface and structural characteristics of the ZrO2 phase as well as the interaction between CuO-ZrO2 species depend strongly on the CuO content. The results also indicated that ZrO2 support was comprised of monoclinic and tetragonal phases with macropores. An increase of the volume of monoclinic ZrO2 phase was observed after impregnation of 10 wt. % of CuO; however, stabilization of tetragonal ZrO2 phase was noticed after loading of 20 wt. % CuO. The presence of low-angle XRD peaks indicates that mesoscopic order is preserved in the calcined CuO-ZrO2 catalysts. XRD reflections due to CuO phase were not observed in case of 10 wt. % CuO supported ZrO2 sample; in contrast, the presence of crystalline CuO phase was observed in 20 wt. % CuO supported ZrO2 sample. The mesoporous 10 wt. % CuO supported ZrO2 catalyst showed stable catalytic activity for several reaction cycles. The observed high catalytic activity of this catalyst could be attributed to the presence of a higher number of dispersed interactive CuO (Cu2+-O-Zr4+) species, easy reducibility, and greater degree of accessible surface Lewis acid sites

Self-decoration of Pt metal particles on TiO2 nanotubes used for highly efficient photocatalytic H2 production

Pt decorated TiO2 has, over the past decades, been a key material for photocatalytic hydrogen production. The present work shows that growing anodic self-organized TiO2 nanotubes from Ti–Pt alloy with a low Pt content of 0.2 at% leads to oxide nanotube layers that are self-decorated with Pt nanoparticles of 4–5 nm in diameter. The average particle spacing is in the range of ~50 nm and is partially adjustable by the anodization conditions. This intrinsic decoration of TiO2 nanotubes with Pt leads to a highly active photocatalyst for the production of H2 under UV or visible light conditions

Single-Particle Spectroscopy of Alcohol-to-Olefins over SAPO-34 at Different Reaction Stages : Crystal Accessibility and Hydrocarbons Reactivity

Insitu synchrotron-based IR and UV/Vis micro-spectroscopy combined with isotopically labeled reactants have been used to identify the different hydrocarbon species formed as well as to assess the activity and accessibility of individual 50m-sized SAPO-34 crystals. For the methanol-to-olefins process, two reaction stages can be distinguished. The first involves the formation of methoxy species, protonated dimethyl ether, and polyalkylated benzene (PAB) carbocations, which do not affect the accessibility of the SAPO-34 crystal. In addition, methoxy species are very dynamic during this stage. The second stage is related to the formation of polyaromatic (PA) species concentrated in the outer rim of the crystal, which are bulky and interact with the acid sites and thus alter the overall accessibility of the crystal. In contrast, the ethanol-to-olefins process only consists of one major stage, as the formation of PAB and PA species cannot be separated. Furthermore, the formation of these species is more internal, and coke formation is mainly concentrated in a layer located in the inner part of the SAPO-34 crystal

NH3 treatment of TiO2 nanotubes: from N-doping to semimetallic conductivity

In the present work we show that a suitable high temperature ammonia treatment allows for the conversion of single-walled TiO2 nanotube arrays not only to a N-doped photoactive anatase material (which is already well established), but even further into fully functional titanium nitride (TiN) tubular structures that exhibit semimetallic conductivity

Combined Operando UV/Vis/IR Spectroscopy Reveals the Role of Methoxy and Aromatic Species during the Methanol-to-Olefins Reaction over H-SAPO-34

The methanol-to-olefins (MTO) process over H-SAPO-34 is investigated by using an operando approach combining UV/Vis and IR spectroscopies with on-line mass spectrometry. Methanol, methoxy, and protonated dimethyl ether are the major species during the induction period, whereas polyalkylated benzenes and polyaromatic species are encountered in the active stage of the MTO process. The accessibility of SAPO-34 is linked with the amount of methoxy species, whereas the formation of polyaromatic species that block the pores is the main cause of deactivation. Furthermore, the reaction pathways responsible for the formation of olefins and polyaromatics co-exist and compete during the whole MTO process, and both routes are directly related to the amount of surface poly alkylated benzene carbocations and methoxy species. Hence, a first-order kinetic model is proposed and comparable activation energies for both processes are obtained