Miranda-Sanchez J.,Research Center e Innovacion Tecnologica |
Elizalde I.,National Polytechnic Institute of Mexico |
Hernandez-Perez I.,Escuela Superior de Ingenieria Quimica e Industrias Extractivas ESIQIE IPN |
Jaramillo-Vigueras D.,Research Center e Innovacion Tecnologica |
Ramirez-Lopez R.,Escuela Superior de Ingenieria Quimica e Industrias Extractivas ESIQIE IPN
Journal of Sol-Gel Science and Technology | Year: 2015
Abstract: The paper presents the results of the authors regarding the synthesis of TiO2–CeO2 mixed oxides using different precursors: (1) titanium isopropoxide and (2) titanium butoxide with different ceria loadings. The samples were characterized from chemical, structural and morphological point of view. The obtained powders were used as support for Pt–Rh impregnation and the influence the Pt–Rh in reduction of the support was established. From XPS, TPR and EPR analysis it was concluded that Ce3+ species are present in higher proportion (>50 %) in series supported Pt–Rh catalysts and it was taken as indicative of oxygen mobility. Correlation between ceria loading and percentage of Ce3+ in catalytic samples was observed. It was also evident that Rh addition allows increasing the reducibility of materials due to interactions metal-support. © 2015, Springer Science+Business Media New York.
Correlation of structural characterization and viscosity measurements with total unsaturation: An effective method for controlling ozonation in the preparation of ozonated grape seed and sunflower oils
Guerra-Blanco P.,Escuela Superior de Ingenieria Quimica e Industrias Extractivas ESIQIE IPN |
Poznyak T.,Escuela Superior de Ingenieria Quimica e Industrias Extractivas ESIQIE IPN
European Journal of Lipid Science and Technology | Year: 2015
Ozonated oils have demonstrated promising results for clinical applications. The reaction of ozone with the unsaturated compounds of oils produces by-products such as ozonides and poly peroxides. A deeper knowledge of the dynamics of by-product formation is helpful in determining the required ozonation degree to obtain therapeutic effects. The aim of this paper is to show the relationship between ozonation degree and structural and viscosity changes during the ozonation of grape seed (GS) and sunflower (SF) oils. Structural characterization was done by Fourier transform infrared (FT-IR) and hydrogen-1 nuclear magnetic resonance (1H NMR) spectroscopy, with iso-ozonides being identified. Viscosity showed a significant increase during ozonation, a fact associated with poly peroxide formation. We have made use of the total unsaturation (TU) method to measure the ozonation degree. The TU of non-ozonated GS oil was found to be higher than for SF oil (5.94 and 4.49mmol per g of oil, respectively), and their by-product distributions were also found to differ. In GS oil, three reaction steps were observed for double-bond conversion into iso-ozonides and poly peroxides, while the ozonides and poly peroxides were formed in parallel in SF oil. The studies we implemented characterized the differences in the reactivities of these oils with ozone. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Estudillo-Wong L.A.,Laboratorio Of Electroquimica Y Corrosion |
Arce-Estrada E.M.,Escuela Superior de Ingenieria Quimica e Industrias Extractivas ESIQIE IPN |
Alonso-Vante N.,University of Poitiers |
Manzo-Robledo A.,Laboratorio Of Electroquimica Y Corrosion
Catalysis Today | Year: 2011
The electrochemical reduction of nitrate ions was carried out on Pt-based nanoparticles supported on carbon Vulcan and deposited on a glassy carbon electrode. Different materials were evaluated: synthesized Pt10/C, Pt-Sny/C (y = 10, 20 wt.%) and commercial Ptx/C-ETEK (x = 10, 20 and 40 wt.%). Cyclic voltammetry technique was used for this purpose. It was found that the catalytic activity for hydrogen evolution reaction (HER) and nitrate electro-reduction (NER) follows the order Pt10/C > Pt 40/C-ETEK > Pt-Sn20/C > Pt20/C-ETEK > Pt-Sn10/C > Pt10/C-ETEK. The electrochemically active surface area (ECSA), charge due to nitrate electro-reduction (QNO3-), and kinetic parameters were calculated in order to understand the catalytic behavior. © 2010 Elsevier B.V. All rights reserved.