RICARDO MARCELO PIASENTIN

RICARDO MARCELO PIASENTIN

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Partial oxidation of methane and generation of electricity using a PEMFC
2019 - NANDENHA, J.; PIASENTIN, R.M.; SILVA, L.G.M.; FONTES, E.H.; NETO, A.O.; SOUZA, R.F.B. de
The aim of this work was to produce methanol through partial oxidation of methane. The gas fed in a solid membrane reactor- PEM fuel cell type (H2/H2O2 + CH4) has been used for electrosynthesis of methanol at room temperature, with electricity cogeneration as a benefit. It was observed that the current density measured when injected CH4 in the cathode decreased about 45%. This occurs due to the conversion of methane inmethanol in some ranges of potentials. In the other hand, in lower ranges of cell potential, formaldehyde was found. In this work, methane was injected on the cathode together with H2O2 solution, where it was observed that the catalytic layer adsorbed CH4 and H2O2 in active sites, which produced OH− radicals that reacted with the hydrocarbon.
The effect of antimony-tin and indium-tin oxide supports on the catalytic activity of Pt nanoparticles for ammonia electro-oxidation
2016 - SILVA, JULIO C.M.; PIASENTIN, RICARDO M.; SPINACE, ESTEVAM V.; NETO, ALMIR O.; BARANOVA, ELENA A.
Platinum nanoparticles supported on carbon (Pt/C) and carbon with addition of ITO (Pt/C-ITO (In2O3)(9)center dot(SnO2)(1)) and ATO (Pt/C-ATO (SnO2)(9).(Sb2O5)(1)) oxides were prepared by sodium borohydride reduction method and used for ammonia electro-oxidation reaction (AmER) in alkaline media. The effect of the supports on the catalytic activity of Pt for AmER was investigated using electrochemical (cyclic voltammetry and chronoamperometry) and direct ammonia fuel cell (DAFC) experiments. X-ray diffraction (XRD) showed Pt peaks attributed to the face-centered cubic (fcc) structure, as well as peaks characteristic of In2O3 in ITO support and cassiterite SnO2 phase of ATO support. According to transmission electron micrographs the mean particles sizes of Pt over carbon were 5.4, 4.9 and 4.7 nm for Pt/C, Pt/C-ATO and Pt/C-ITO, respectively. Pt/C-ITO catalysts showed the highest catalytic activity for ammonia electrooxidation in both electrochemical and fuel cell experiments. We attributed this to the presence of In2O3 phase in ITO, which provides oxygenated or hydroxide species at lower potentials resulting in the removal of poisonous intermediate, i.e., atomic nitrogen (N-ads) and promotion of ammonia electrooxidation. (C) 2016 Elsevier B.V. All rights reserved.
PtBi/C electrocatalysts for formic acid electro-oxidation in acid and alkaline electrolyte
2015 - YOVANOVICH, M.; PIASENTIN, R.M.; AYOUB, J.M.S.; NANDENHA, J.; FONTES, E.H.; SOUZA, R.F.B. de; BUZZO, G.S.; SILVA, J.C.M.; SPINACE, E.V.; ASSUMPCAO, M.H.M.T.; NETO, A.O.; SILVA, S.G. da
Electro-oxidation of ethanol of PtPdSn/C-Sbsub(2)Osub(5)-SnOsub(2) electrocatalysts prepared by borohydride reduction
2013 - PIASENTIN, R.M.; SOUZA, R.F.B. de; SILVA, J.C.M.; SPINACE, E.V.; SANTOS, M.C.; OLIVEIRA NETO, A.
Pt/C-Sb2O5.SnO2, PtPd/C-Sb2O5.SnO2 and PtPdSn/C-Sb2O5.SnO2 electrocatalysts were prepared in a single step using H2PtCl6.6H2O, Pd(NO3)2.2H2O and SnCl2.2H2O as metal sources, sodium borohydride as reducing agent and a physical mixture of 85% Vulcan Carbon XC72 and 15% Sb2O5.SnO2 (antimony tin oxide – ATO) as support. X-ray diffractograms showed that Pt-Pd-Sn(fcc) alloy, carbon and Sb2O5.SnO2 phases are present in the PtPdSn/C-Sb2O5.SnO2 electrocatalysts. Transmission electron microscopy for all electrocatalysts showed that the metal nanoparticles were homogeneously distributed over the supports with average particle sizes in the range of 3-5 nm. The electro-oxidation of ethanol was studied by cyclic voltammetry and chronoamperometry at 25oC and in a single Direct Ethanol Fuel Cell (DEFC) at 100oC. PtPdSn/C-Sb2O5.SnO2 electrocatalysts exhibited superior performance for ethanol electro-oxidation than PtPd/C-Sb2O5.SnO2 and Pt/C-Sb2O5.SnO2 electrocatalysts, respectively. In situ FTIR studies showed that acetic acid and CO2 are preferentially formed using PtPdSn/C-Sb2O5.SnO2 electrocatalysts.
PtRu/C and PtRuBi/C electrocatalysts prepared in two different ways by borohydride reduction for ethanol electro-oxidation
2010 - BRANDALISE, MICHELE; TUSI, MARCELO M.; PIASENTIN, RICARDO M.; LINARDI, MARCELO; SPINACE, ESTEVAM V.; OLIVEIRA NETO, ALMIR