High-porosity nanostructured amorphous tungsten OXIDE (a-WO₃) films were synthesized by a Hot Filament Chemical Vapor Deposition technique (HFCVD) and then transformed into a crystalline WO₃ by simple thermal annealing. The a-WO₃ films were annealed at 100, 300, and 500 °C for 10 min in an air environment. The films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), micro-Raman spectroscopy, high-resolution transmission electron microscopy (HR-TEM), and UV–vis spectroscopy. Results revealed that the a-WO₃ films were highly porous, composed of cauliflower-like structures made of nanoparticles with average sizes of 12 nm. It was shown that the effect of annealing on the morphology of the a-WO₃ films leads to a sintering process. However, the morphology is conserved. It was found that at annealing temperatures of 100 °C, the a-WO₃ films are of an amorphous nature, while at 300 °C, the films crystallize in the monoclinic phase of WO₃. The calculated bandgap for the a-WO₃ was 3.09 eV, and 2.53 eV for the film annealed at 500 °C. Finally, the results show that porous WO₃ films preserve the morphology and maintain the porosity, even after the annealing at 500 °C.

Chitosan-added NiMoP catalysts supported on alumina and alumina-titania were studied in the hydrodesulfurization (HDS) of dibenzothiophene (DBT). The preparation of catalysts containing Mo (12 wt%), Ni (3 wt%), P (1.6 wt%), and chitosan/nickel = 2 (mol ratio) was accomplished by sequential pore-filling impregnation varying the order of chitosan integration. Materials were characterized by DRIFTS, TPR, TG-DTA, and XPS techniques. The TG-DTA study showed that the nature of the support influences the degradation of chitosan onto the catalytic materials and also influences the HDS of DBT and the product distribution as well. The series of catalysts supported on alumina presented the most remarkable effect of chitosan, in which the OH and NH groups of the organic molecule interact with acid sites of the support weakening the interaction between alumina and deposited metal phases. In all cases, DBT was converted mainly through direct sulfur removal. The catalysts ChP3/A (alumina support impregnated with chitosan in phosphoric acid solution, prior to NiMoP deposition) and ChP4/AT (alumina-titania support impregnated with NiMoP solution, prior to contacting with a solution comprising chitosan and phosphorus) exhibited the best performance in HDS reactions and also showed the highest selectivity in biphenyl formation. Presence of carbonaceous residua on the catalyst’s surface, as shown by XPS, could enhance the HDS activity over the ChP4/AT sample.

The effect of the preparation method of monometallic Pd and Pt and bimetallic Pd-Pt/Al₂O₃-TiO₂catalysts on the hydrodesulfurization (HDS) of dibenzothiophene (DBT) was investigated in this study. The synthesis was accomplished using three methods: (A) impregnation, (B) metal organic chemical vapor deposition (MOCVD), and (C) impregnation-MOCVD. The bimetallic Pd-Pt catalyst prepared by the impregnation-MOCVD method was most active for the HDS of DBT compared to those prepared by the single impregnation or MOCVD method due to the synergetic effect between both noble metals. The greater selectivity toward biphenyl indicated that this bimetallic Pd-Pt catalyst preferentially removes sulfur via the direct desulfurization mechanism. However, the bimetallic Pd-Pt catalyst prepared using the single MOCVD method did not produce any cyclohexylbenzene, which is most likely associated with the hydrogenation/dehydrogenation sites.

The preparation of two new bisoxazolidines, two N-(2-hydroxyethyl)- N-alkylglycine derivatives and two morpholones is described. The structure of (5S, 6R)-N-isopropyl-5-methyl-6-phenyl-l, 4-oxazin-2-one was established by X-ray crystallographic analysis. Supplementary Material available: Tables of atomic coordinates, thermal parameters, bond lengths and angles and observed and calculated structure factors have been deposited at the Cambridge Crystallographic Data Center.