نتایج جستجو برای: gamma alumina γ al2o3
تعداد نتایج: 211442 فیلتر نتایج به سال:
Alumina nanorods were prepared from chromium-containing alumina sludge, and the effects of doping elements, such as Cr, Fe, and Mg, were researched. The results show that the crystal transformation of alumina is restricted by the doped Cr and facilitated by the doped Fe and Mg, which is transformed from θ-Al2O3 to α-Al2O3 in the calcination process. Meanwhile, the crystal transformation of alum...
Palladium catalysts containing Pd(II) supported on Al2O3 and alumina-based mixed oxides, Al2O3-ZrO2, Al2O3-CeO2, and Al2O3-Fe2O3, are very effective in the Heck coupling of iodobenzene with cyclohexene in DMF solution. The best results, up to 81% of monoarylated products with a selectivity to 4-phenylcyclohexene (3) close to 90% were obtained with KOH as a base. The catalytic activity of pallad...
Atomic layer deposition (ALD) was used to prepare a thin alumina on Fischer–Tropsch catalysts. Co-Pt-Si/γ-Al2O3 catalyst overcoated with 15–40 cycles of Al2O3 deposited from trimethylaluminum (TMA) and water vapor, followed by thermal annealing. The resulting tailored 35 cycle ALD overcoating had increased activity compared unmodified catalyst. increase in achieved without significant loss sele...
The separation of H2O vapor from (hydrogen-rich) gaseous streams is a topic increasing interest in the context CO2 valorisation, where situ water removal increases product yield and catalyst stability. In this work, composite alumina carbon molecular sieve membranes (Al-CMSM) were prepared phenolic resin solutions loaded with hydrophilic boehmite (γ-AlO(OH)) nanosheets (0.4–1.4 wt. % solution) ...
Mesoporous gamma alumina fibres of high surface area, stable up to 1000 oC, were synthesized by bioreplica technique using sisal fibres as templates. Alumina formation during pyrolysis and calcination of fibres infiltrated with aluminium chloride solution has been studied, paying special attention to the interaction between the precursor and sisal fibres, using several experimental techniques s...
Hybrid intermetallic composites (HICs-aluminum based matrix, new hybrid design) reinforced with titanium nitride (TiN) and alumina (γ-Al2O3) were designed manufactured through the innovative combined method of sinter + forging. This results in highly dense materials with, general, improved mechanical properties. In TiN content was varied (10, 20 30 wt %) but γ-Al2O3 kept constant at 10 wt%. Add...
A multilayer composite ceramic membrane was prepared by depositing a nano-scale layer of SiO2 on top of a modified porous alumina support by chemical vapor deposition (CVD) method. The modification of the support was carried out by adding a graded layer of Al2O3 (γ-alumina phase), using sol-gel method. An optimized temperature of 700 K for intermediate layer calcination was gained by XRD analys...
The paper relates to a catalyst, comprising copperchromium spinel, coated on carrier γ-Al2O3. The effect of preparation conditions on the active component composition and activity behavior of the catalysts is discussed. It was found that the activity of carbon monoxide, DME, formaldehyde and methanol oxidation reaches a maximum at an active component content of 20 – 30 wt. %. Temperature calcin...
This paper reports results of a study regarding the activities of nano structure Mn/γ-Al2O3 and γ-Al2O3 catalysts for oxidation of 2-propanol (as a model of volatile organic compound). Nanostructure of catalysts was revealed using XRD, SEM and TEM techniques. Catalytic studies were carried out in U-shaped packed bed reactor under atmospheric pressure and at the reaction temperature of 150- 500°...
Plasma electrolytic oxidation (PEO) was applied using a pulsed unipolar waveformto produce Al2O3−TiO2 composite coatings from sol solutions containing colloidal TiO2 nanoparticles. The were produced by dissolving 1, 3, and 5 g/L of potassium titanyl oxalate (PTO) in silicate solution. Scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction, Raman spectroscopy to characte...
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