Centro de Investigación y Desarrollo Tecnológico en Electroquímica

About: Centro de Investigación y Desarrollo Tecnológico en Electroquímica is a based out in . It is known for research contribution in the topics: Cyclic voltammetry & Catalysis. The organization has 537 authors who have published 682 publications receiving 10382 citations. The organization is also known as: Centro de Investigacion y Desarrollo Tecnologico en Electroquimica & Center of Research and Technologic Development in Electrochemistry.

Highly Photoluminescent Sulfide Clusters Confined in Zeolites

Abstract: The design, synthesis and photoluminescence characterization of sulfide cluster-based zeolitic materials with the general formula Na8[SiAlO4]6SxCl2–2x is presented in this report. The employed experimental conditions, which included the thermal treatment of sodium Linde type A (Na-LTA) zeolites in the presence of Na2SO4 and NaCl, yielded highly photoluminescent sulfur-zeolites with remarkably large Stokes shifts. An emission band at 650 nm for samples with low sulfur contents is observed when excited at 380 nm, which is fully consistent with S2– clusters as light-emitting centers. These orange emitting materials display external quantum efficiencies (EQEs) reaching 53% with peculiar high temperature photoluminescence stability up to 450 °C. For higher S/Cl molar ratios, a gradual conversion to near-infrared (NIR) light-emitting centers is observed with a maximum at 780 nm. This novel NIR luminescent species with EQEs of about 10% are attributed to polysulfide clusters (tentatively S42– species). Given the...

In Situ Surface-Enhanced Raman Spectroscopy Study of the Electrocatalytic Effect of PtFe/C Nanocatalyst on Ethanol Electro-Oxidation in Alkaline Medium

Abstract: Currently, the ethanol electro-oxidation reaction has attracted considerable attention in fuel cells because of new green ethanol synthetic methods based on biomass processes that have emerged. In this study, PtFe/C and Pt/C nanoparticles were synthesized by a chemical reduction method and tested in the ethanol electro-oxidation reaction. Furthermore, the electrocatalytic effect of the PtFe bimetallic catalyst was analyzed by in situ surface-enhanced Raman spectroscopy (SERS) coupled to an electrochemical cell. X-ray diffractograms showed typical face-centered cubic structures with crystallite sizes of 3.31 and 3.94 for Pt/C and PtFe/C, respectively. TEM micrographs revealed nanoparticle sizes of 2 ± 0.4 nm and 3 ± 0.6 nm for Pt/C and PtFe/C respectively. PtFe/C exhibited a Pt90Fe10 composition by both X-ray fluorescence and energy-dispersive X-ray spectroscopy. A better electrocatalytic activity as function of concentration was obtained through the incorporation of a small amount of Fe into the Pt lattice and the presence of Fe2+/Fe3+ (observed by X-ray photoelectron spectroscopy). According to SERS experiments, the presence of these iron species promotes the chemisorption of ethanol, the formation of formic acid as main product and renewal of the catalytic sites, resulting in current densities that were at least three fold higher than the values obtained for the Pt/C nanocatalyst.