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Abstract  

Properties of two catalysts tailored in the laboratory conditions by sulfation of commercial Zr-hydroxide and Zr-hydroxide of nitrate origin were compared with those of commercial SO4-Zr-hydroxide. Equally thermally treated samples in the temperature interval 500–700°C, and having the same amount of sulfur, show different properties indicating memory effect of their solid parent materials. The catalyst obtained by sulfation of commercial Zr-hydroxide differs in amount of residual sulfates upon calcination from other two catalysts. The instability of sulfates in the previous case might be connected to the lowest surface area values of catalyst and the highest fraction of monoclinic phase observed at all applied calcination temperatures.

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Abstract  

The purified bentonite parent clay, fraction ≤; 2 mm of montmorillonite type, has been pillared by various polyhydroxy cations, Al, AlFe and AlCu, using conventional pillaring methods. The thermal behavior of PILCs was investigated by combination of X-ray diffraction (XRD), thermal analysis (DTA, TG) and low temperature N2 adsorption/desorption (LTNA). Thermal stability of Al-, AlFe- and AlCu-PILC samples was estimated after isothermal pretreatment in static air on the temperatures 300, 500, 600 and 900C. Crucial structural changes were not registered up to 600C, but the fine changes in interlayer surrounding and porous/microporous structure being obvious at lower temperatures, depending on the nature of the second pillaring ion. AlFe-PILC showed higher thermal stability of the texture, the AlCu-PILC having lower values and lower thermal stability concerning both overall texture and micropore surface and volume. Poorer thermal stability of AlCu-PILC sample at higher temperatures was confirmed, the presence of Cu in the system contributing to complete destruction of aluminum silicate structure, by 'extracting' aluminum in stabile spinel form.

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confectionary systems. Here, we investigated differences in the texture properties, the viscosity and thermal properties of the blends. Materials and methods Commercial sugar (sucrose), stevia and xylitol were used in this study. Palm oil was purchased from

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Reaction Kinetics, Mechanisms and Catalysis
Authors: Cleanio L. Lima, Hélvio S. A. de Sousa, Santiago J. S. Vasconcelos, Josué M. Filho, Alcemira C. Oliveira, Francisco F. de Sousa, and Alcineia C. Oliveira

by the Raman results. This fact limits the selectivity to acrolein and hydroxyacetone due to the heavy compound formation. In addition, the characteristics of the sulfated AlSBA-15 molecular sieve in terms of acidity, textural properties and

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different precursors with a zirconium loading of 2% (w/w) and palladium loading of 0.5% (w/w). One of the routes employed in this work is the sol-gel method, known as a route that provides the possibility to control the textural properties of materials. In

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Reaction Kinetics, Mechanisms and Catalysis
Authors: Valeria Palermo, Ángel G. Sathicq, Patricia G. Vázquez, Horacio J. Thomas, and Gustavo P. Romanelli

adsorption technique. These catalysts were well characterized by means of 31 P-NMR, UV–visible spectra, FT-IR spectra, thermal analysis, and textural properties. Mo, V and Bi amounts were estimated by ICP-AES analysis. Experimental

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heating. Microwaved doughs’ exterior remains tough while the interior is hard and chewy [ 2 ]. These and other deleterious textural properties have been discussed elsewhere [ 3 – 7 ]. Par-baking the dough prior to reheating improves bread quality

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Introduction Hazelnut spreads are considered as a complex multiphase system, which contain different dispersed solid particulars and a continuous fat phase ( Glicerina et al., 2013 ). The physical attributes such as textural properties, viscosity

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Abstract  

The effect of the iron precursor on the thermal decomposition of iron oxyhydroxides was studied by DSC, DTA and TG in this work. Samples were prepared from iron nitrate, iron sulfate and iron chloride and the thermal curves obtained were analyzed by specific area measurements, X-ray diffraction and Mssbauer spectroscopy. It was found that the iron oxyhydroxide precursors affect the temperatures of the hematite formation as well as the textural properties of the final hematite producing particles with different diameters as following: iron sulfate (3.3 nm)<iron nitrate (15 nm)<iron chloride (24 nm).

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Abstract  

Pt/MCM, Pt/SiO2, Pd/MCM and Pd/SiO2 were prepared and characterized by H2-TPR, TEM, 29Si-CP-MAS-NMR, DRS-UV-Vis and tested in the hydrodechlorination of 1,2-dichloroethane. Differences in the catalytic behavior were related with textural properties.

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