JAMIL MAHMOUD SAID AYOUB
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Artigo IPEN-doc 26619 Activation of methane on PdZn/C electrocatalysts in an acidic electrolyte at low temperatures2019 - NANDENHA, J.; NAGAHAMA, I.H.F.; YAMASHITA, J.Y.; FONTES, E.H.; AYOUB, J.M.S.; SOUZA, R.F.B. de; FONSECA, F.C.; NETO, A.O.PdZn/C electrocatalysts were prepared by sodium borohydride utilized as reducing agent for activation methane in an acidic medium at room temperature and in a proton exchange membrane fuel cell (PEMFC) at 80°C. The materials prepared were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The diffractograms of the PdZn/C electrocatalysts showed only peaks associated with Pd face-centered cubic (fcc) structure. Cyclic voltammograms (CV) of all electrocatalysts after adsorption of methane shown an increment in current during the anodic scan, this effect was more pronounced for Pd(70)Zn(30)/C. In situ ATR-FTIR (Attenuated Total Reflectance-Fourier Transform Infrared) experiments was not observed the formation of intermediates adsorbed for PdZn/C electrocatalysts, this behavior indicated that the methane oxidation occurs by parallel mechanisms. Polarization curves at 80°C in PEMFC show that Pd(90)Zn(10)/C has superior performance over the other electrocatalysts in methane oxidation.Artigo IPEN-doc 25731 Methanol oxidation in acidic and alkaline electrolytes using PtRuIn/C electrocatalysts prepared by borohydride reduction process2018 - SANTOS, M.C.L.; NANDENHA, J.; AYOUB, J.M.S.; ASSUMPÇAO, M.H.M.T.; NETO, A.O.PtRuIn/C electrocatalysts (20% metal loading by weight) were prepared by sodium borohydride reduction process using H2PtCl66H2O, RuCl3xH2O and InCl3xH2O as metal sources, borohydride as reducing agent and Carbon Vulcan XC72 as support. The synthetized PtRuIn/C electrocatalysts were characterized by X-ray diffraction (XRD), energy dispersive analysis (EDX), transmission electron microscopy (TEM), cyclic voltammetry (CV), chronoamperommetry (CA) and polarization curves in alkaline and acidic electrolytes (single cell experiments). The XRD patterns show Pt peaks are attributed to the face-centered cubic (fcc) structure, and a shift of Pt (fcc) peaks indicates that Ru or In is incorporated into Pt lattice. TEM micrographs show metal nanoparticles with an average nanoparticle size between 2.7 and 3.5 nm. Methanol oxidation in acidic and alkaline electrolytes was investigated at room temperature, by CV and CA. PtRu/C (50:50) shows the highest activity among all electrocatalysts in study considering methanol oxidation for acidic and alkaline electrolyte. Polarization curves at 80°C show PtRuIn/C (50:25:25) with superior performance for methanol oxidation, when compared to Pt/C, PtIn/C and PtRu/C for both electrolytes. The best performance obtained by PtRuIn/C (50:25:25) in real conditions could be associated with the increased kinetics reaction and/or with the occurrence simultaneously of the bifunctional mechanism and electronic effect resulting from the presence of Pt alloy.Artigo IPEN-doc 18325 Ethanol electro-oxidation on PtSn/C-ATO electrocatalysts2012 - AYOUB, J.M.S.; SOUZA, R.F.B. de; SILVA, J.C.M.; PIASENTIN, R.M.; SPINACE, E.V.; SANTOS, M.C.; OLIVEIRA NETO, A.Artigo IPEN-doc 17734 Preparation of Pt/C-Insub(2)Osub(3).SnOsub(2) electrocatalysts by borohydride reduction process for ethanol electro-oxidation2012 - HENRIQUE, R.S.; SOUZA, R.F.B. de; SILVA, J.C.M.; AYOUB, J.M.S.; PIASENTIN, R.M.; LINARDI, M.; SPINACE, E.V.; SANTOS, M.C.; NETO, A.O.Artigo IPEN-doc 15550 The performance of Pt nanoparticles supported on Sbsub(2)Osub(5).SnOsub(2), on carbon and on physical mixtures of Sbsub(2)Osub(5).SnOsub(2) and carbon for ethanol electro-oxidation2010 - OLIVEIRA NETO, A.; BRANDALISE, M.; DIAS, R.R.; AYOUB, J.M.S.; SILVA, A.C.; PENTEADO, J.C.; LINARDI, M.; SPINACE, E.V.