Laboratorio Of Electroquimica Y Corrosion

Mexico City, Mexico

Laboratorio Of Electroquimica Y Corrosion

Mexico City, Mexico

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Oliver-Tolentino M.A.,Laboratorio Of Investigacion En Materiales Porosos | Guzman-Vargas A.,Laboratorio Of Investigacion En Materiales Porosos | Manzo-Robledo A.,Laboratorio Of Electroquimica Y Corrosion
ECS Transactions | Year: 2010

The electrochemical response of modified electrode with Cu-ZSM5 deposited on glassy carbon surface has been studied using cyclic voltammetry and open circuit potential (OCP) measurements. The i-E characteristics showed two cathodic processes at c.a. 0.03V and -0.2V/SCE attributed to the formation of Cu+ and Cu0, respectively. The progressive spread of electro active species on the surface of the zeolite was observed by multi sweep cyclic voltammetry experiment. The diffusion of Cu2+ in the ZSM5 layers depends on the cation nature and increases in the order Li +>K+>NH4 +>Na+. The evaluation of reversible behavior indicated that the electrochemical process is affected by adsorption/desorption phenomena at the interface. It was found that the redox processes are proportional to the amount of Cu species in the zeolite structure. ©The Electrochemical Society.


Estudillo-Wong L.A.,Laboratorio Of Electroquimica Y Corrosion | Vargas-Gomez A.M.,Laboratorio Of Electroquimica Y Corrosion | Arce-Estrada E.M.,Escuela Superior de Ingenieria Quimica e Industrias Extractivas | Manzo-Robledo A.,Laboratorio Of Electroquimica Y Corrosion
Electrochimica Acta | Year: 2013

The electro-oxidation of methanol was studied in alkaline solution on Pd nanoparticles supported on carbon black (XC-72R, C) and TiO2/C composite. The materials were prepared via organic colloid route at 170 C with 5 wt% of Pd. X-ray diffraction (XRD), PdO monolayer reduction (PdOred) and CO-stripping was employed to characterize both structure and electrochemical properties. According to this, the lattice parameter decreases from 0.3991 to 0.3905 nm due to a possible formation of Pd-Ti alloy. This modification is linked with the electrochemical active surface area (ECSA) decreasing from 22 to 18 m2 g-1. On the other hand, studies as a function of temperature and alcohol concentration indicated that the current for methanol electro-oxidation is higher and more stable at Pd/TiO2-C, with Ea = 44.042 kJ mol-1. Then, it is highly possible that at Pd/TiO2-C, the OH-/OH ads couple is adsorbed at the TiO2 sites, increasing the kinetic of methanol oxidation reaction at the catalyst surface. © 2013 Published by Elsevier Ltd.


Estudillo-Wong L.A.,Laboratorio Of Electroquimica Y Corrosion | Arce-Estrada E.M.,Escuela Superior de Ingenieria Quimica e Industrias Extractivas | Manzo-Robledo A.,Laboratorio Of Electroquimica Y Corrosion
Electrochimica Acta | Year: 2014

The electroreduction of nitric oxide (NO) in alkaline media was carried out on Pt nanoparticles (5 wt.% Pt), which were synthesized by the carbonyl route. The as-prepared materials were supported on Carbon Black (XC-72R, C) and TiO2-C composite (10 wt.% TiO2) and deposited on glassy carbon (GC) electrode. X-ray Diffraction (XRD), CO-stripping and hydrogen adsorption-desorption (Hupd) analysis were employed to characterize the structure and electrochemical properties. According to XRD patterns, the particle size increases from 3.95 to 8.98 nm due to the interaction of Pt with TiO2 in the carbon matrix. This modification promotes a better performance during CO-oxidation and proton adsorption-desorption. As a consequence, the performance toward NO-reduction was more important in TiO 2-C composite, linked with the electrochemical active-surface area and chemical surface area relationship (ECSA/CSA). It was found that the mechanism for the reduction of nitric oxide toward nitrogen is a bi-functional process with coupled chemical and electrochemical interfacial-reactions with NH2 specie as intermediate, as demonstrated by the induced reduction reaction of NO2 - and NO2 - + NO, and UV-vis spectrometry. © 2014 Elsevier Ltd.


Estudillo-Wong L.A.,Laboratorio Of Electroquimica Y Corrosion | Santillan-Diaz G.,Laboratorio Of Electroquimica Y Corrosion | Arce-Estrada E.M.,Escuela Superior de Ingenieria Quimica e Industrias Extractivas | Alonso-Vante N.,CNRS Poitiers Institute of Chemistry: Materials and Natural Resources | Manzo-Robledo A.,Laboratorio Of Electroquimica Y Corrosion
Electrochimica Acta | Year: 2013

The electroreduction of nitrogen species in alkaline medium was performed on platinum nanoparticles (1-2 nm) with metal loadings of 5 and 10 wt% Pt, synthesized by the chemical carbonyl route. The electrochemically active surface analysis evidences that the real surface area is concomitant to the Pt-loading in the support. The electrochemical analysis put in evidence that nitrite ions were reduced from -0.6 to -0.78 V and the charge transfer step is attributed to the NO2-/NO redox couple. The Tafel slope analysis confirms that from Ep to -0.78 V the reduction of NO occurs via an ECE mechanism. An analysis of Nicholson-Shain schemes and NO-saturated in solution verified these results. © 2012 Elsevier Ltd. All rights reserved.


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.


Aragon-Gonzalez G.,Metropolitan Autonomous University | Leon-Galicia A.,Metropolitan Autonomous University | Gonzalez-Huerta R.,Laboratorio Of Electroquimica Y Corrosion | Camacho J.M.R.,Metropolitan Autonomous University | Uribe-Salazar M.,Metropolitan Autonomous University
Journal of Physics: Conference Series | Year: 2015

A PEM electrolyser for hydrogen production was evaluated. It was fed with water and a 400 mA, 3.5 V cc electrical power source. The electrolyser was built with two acrylic plates to form the anode and the cathode, two meshes to distribute the current, two seals, two gas diffusers and an assembly membrane-electrode. A small commercial neoprene sheet 1.7 mm thin was used to provide for the water deposit in order to avoid the machining of the structure. For the assembly of the proton interchange membrane a thin square 50 mm layer of Nafion 115 was used. © Published under licence by IOP Publishing Ltd.


Oliver-Tolentino M.A.,National Polytechnic Institute of Mexico | Vazquez-Samperio J.,Laboratorio Of Investigacion En Materiales Porosos | Manzo-Robledo A.,Laboratorio Of Electroquimica Y Corrosion | Gonzalez-Huerta R.D.G.,Laboratorio Of Electroquimica Y Corrosion | And 3 more authors.
Journal of Physical Chemistry C | Year: 2014

In the present work, the hydrotalcite-like materials known as layered double hydroxides (LDHs) were synthesized. The Ni-Al and Ni-Fe materials with different Ni/Fe ratio were obtained by coprecipitation method at variable pH. The LDH structure was verified by X-ray diffraction, Fourier transform infrared, and Raman spectroscopy. No secondary extra phases were observed for any material. The electronic properties were evaluated by UV-vis spectroscopy, while the magnetic ones were followed by electron paramagnetic resonance (EPR). The results suggested that sample H/Ni-Fe2 (Ni/Fe = 2) has a ferrimagnetic behavior as a result of the combined action of NiII-OH-NiII, FeIII-OH-NiII, and FeIII-OH-FeIII pairs across the layers and ferromagnetic interactions operating between layers. Furthermore, the material H/Ni-Fe1 (Ni/Fe = 1.5) showed a combination of paramagnetic and ferromagnetic interactions which favors a superexchange interaction among metal centers through the OH bridges across the cationic sheets; the superexchange interaction enhances the electrocatalytic activity on the oxygen evolution reaction (OER) in alkaline media. On the other hand, XPS experiments showed that the H/Ni-Fe1 did not exhibit structural changes after electrochemical processes. The activity toward the OER was in the order H/Ni-Fe1 > H/Ni-Fe2 > H/Ni-Al, as was confirmed using in situ linear sweep voltammetry (LSV) coupled with mass spectrometry (differential electrochemical mass spectrometry). © 2014 American Chemical Society.


Vazquez-Cuchillo O.,Autonomous University of Nuevo León | Manzo-Robledo A.,Laboratorio Of Electroquimica Y Corrosion | Zanella R.,National Autonomous University of Mexico | Elizondo-Villareal N.,Autonomous University of Nuevo León | Cruz-Lopez A.,Autonomous University of Nuevo León
Ultrasonics Sonochemistry | Year: 2013

NaTaO 3 perovskite-like materials were synthesized using sodium acetate and tantalum ethoxide as precursors in an ultrasonic bath at room temperature. The pristine sample was thermally treated at 600 °C and characterized using XRD, N 2 physisorption, DRS, SEM and TEM techniques. The structural characterization by X-ray powder diffraction revealed that the crystallization of the NaTaO 3 phase prepared at 600 °C showed agglomerates sizes in the micrometric scale, as confirmed by scanning electron microscopy (SEM). On the other hand, well-defined NaTaO 3 particles in the nanometric scale were determined using TEM. It was found that, for the treated sample, the band gap and BET area was 3.8 eV and 9.5 m 2 g -1, respectively. The annealed perovskite, deposited onto ITO glass, presented an important variation in the open circuit potential transient during UV light irradiation in neutral solution, compared with its counterpart prepared by solid-state method. These intrinsic properties, given by the preparation route, might be appropriate for increase its photocatalytic activity. © 2012 Elsevier B.V. All rights reserved.


Oliver-Tolentino M.A.,ESIQIE IPN | Guzman-Vargas A.,ESIQIE IPN | Manzo-Robledo A.,Laboratorio Of Electroquimica Y Corrosion | Martinez-Ortiz M.J.,ESIQIE IPN | Flores-Moreno J.L.,Metropolitan Autonomous University
Catalysis Today | Year: 2011

In order to evaluate the electrocatalytic properties, Mg/Al and Mg/Ca/Al hydrotalcite-like materials (LDHs) and their corresponding mixed oxide were immersed in a carbon paste electrode matrix to obtain the so-called modified carbon paste electrode (MCPE). Previous to preparation of MCPE, LDH materials were characterized by different techniques, as XRD, FTIR and BET analysis. The electrochemical response of the electrodes was characterized in neutral conditions using reactive blue 69 dye as a probe molecule. Linear sweep voltammetry (LSV), cyclic voltammetry (CV), multi-sweep cyclic voltammetry (MSCV) and open circuit potential transient techniques were employed. Different current magnitudes in the oxygen evolution reaction (OER) were found as a function of thermal treatment and supporting electrolyte (pH). On the other hand, in a solution containing 250 ppm of the probe molecule at neutral pH, peaks attributed to blue 69 oxidation were found at ca. 0.65 and 0.95 V/SCE. The presence of calcium, as additional divalent cation, and the rehydration of the mixed oxide, due to memory effect, have a positive performance, increasing the magnitude of the electrocatalytic process. © 2010 Elsevier B.V. All rights reserved.


Oliver-Tolentino M.A.,Laboratorio Of Investigacion En Materiales Porosos | Guzman-Vargas A.,Laboratorio Of Investigacion En Materiales Porosos | Arce-Estrada E.M.,ESIQIE IPN | Ramirez-Rosales D.,ESFM IPN | And 2 more authors.
Journal of Electroanalytical Chemistry | Year: 2013

In the present work the system Cu-ZSM5 was prepared by aqueous ion-exchange method from zeolite H-ZSM5. The solids were characterized by X-ray diffraction, nitrogen physisorption, temperature-programmed reduction with hydrogen (TPR-H2) and electron paramagnetic resonance (EPR). These porous materials were mixed with poly (methacrylic acid methyl ester) and methyl acrylate (MA), and immobilized on a glassy carbon electrode in order to obtain the so-called zeolite-modified electrode (ZME). The as-prepared electrodes were characterized by infrared spectroscopy and electrochemical techniques as cyclic voltammetry and chronocoulometry. The presence of copper in the zeolite was confirmed by TPR-H2. The XRD results indicate not important structural changes in the zeolite ZSM5 due to copper incorporation. The EPR spectroscopy showed that copper in Cu-ZSM5 is as isolated form of Cu 2+ ions. The results of nitrogen physisorption suggest that the Cu2+ cations are occupying the exchange sites in zeolite ZSM5. On the other hand, the IR spectroscopy revealed the presence of C O and C C groups in the mixture Cu-zeolite/polymer. The electrochemical profiles showed that reduction of Cu2+ to Cu0 occurs by two steps in presence of chloride due to stabilization of Cu+. The influence of anion in the electrolyte suggests that the redox processes Cu2+ to Cu + and Cu+ to Cu0 occurs on the zeolite-modified electrode even at nitrate- and sulfate-based solutions at the glassy carbon/zeolite interface. This stabilization is mainly associated to the interactions between Cu+ and C C group and the zeolite framework acting as "electron reservoir".

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