Electrocatalysts
Mostrando 1-12 de 64 artigos, teses e dissertações.
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1. Perovskite-Type Oxides La0.6M0.4Ni0.6Cu0.4O3 (M = Ag, Ba, Ce) towards the Oxygen Reduction Reaction (ORR) in Alkaline Medium: Structural Aspects and Electrocatalytic Activity
In this work, La0.6M0.4Ni0.6Cu0.4O3 (M = Ag, Ba, and Ce, denoted as LANC, LBNC, and LCNC, respectively) electrocatalysts were synthesized by the Pechini method at 1023 K for two hours in air. Rietveld refinement allowed the identification of the crystallographic phases present in all oxides. The electrocatalytic performance of these oxides towards the oxygen
J. Braz. Chem. Soc.. Publicado em: 2021-03
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2. INFLUÊNCIA DA COMPOSIÇÃO DOS NANOFIOS PT-IR/C NA ATIVIDADE CATALÍTICA FRENTE A OXIDAÇÃO ELETROQUÍMICA DE ETANOL EM MEIO ÁCIDO
Carbon-supported platinum-iridium nanowire-shape electrocatalysts containing 20% of metallic loading were synthesized by chemical reduction method using formic acid as a reducing agent and tested towards the oxidation of ethanol in acidic medium. The developed electrocatalysts were synthesized with the following compositions: Pt0.9Ir0.1/C, Pt0.8Ir0.2/C, Pt0.
Quím. Nova. Publicado em: 2020-02
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3. Nanoparticles of Fe2O3 and Co3O4 as Efficient Electrocatalysts for Oxygen Reduction Reaction in Acid Medium
This paper presents a comparative study about the oxygen reduction reaction (ORR) catalyzed by nanoparticles of Fe2O3 and Co3O4 applied on the surface of glassy carbon electrodes (GCE). The nanoparticles were synthesized using the modified polymeric precursor method (Pechini). These two nanomaterials were characterized by Fourier transform infrared spectrosc
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
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4. Iridium-Based Catalysts for the Ethanol Electrooxidation in Acidic Media
Herein we sinthesize and investigate Ir-based nanocatalysts (dispersed in carbon) in different atomic compositions combining two (IrRh) and three metals (IrRhSn). These materials were evaluated towards the ethanol electrooxidation in acidic electrolyte in presence of three ethanol concentrations using cyclic voltammetry, while the species produced during the
J. Braz. Chem. Soc.. Publicado em: 21/10/2019
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5. Addition of CeO2 Nanorods in PtSn-Based Electrocatalysts for Ethanol Electrochemical Oxidation in Acid Medium
This work describes the preparation of Pt/C, PtxSny/C and PtxSny(CeO2 nanorods/C) nanoparticle catalysts synthesized by the chemical reduction method via sodium borohydride for the ethanol oxidation reaction. Using X-ray diffractogram analysis, it was verified that no alloy formation occurred between platinum (Pt) and tin (Sn). The distribution of the nanopa
J. Braz. Chem. Soc.. Publicado em: 12/08/2019
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6. Evaluating the Electrochemical Characteristics of Babassu Coconut Mesocarp Ethanol Produced to Be Used in Fuel Cells
The aim of the present study is to assess the potential of ethanol deriving from the mesocarp of babassu coconut to be used in fuel cells. Babassu ethanol was generated through hydrolysis and fermentation processes. The Pt, PtRh and PtRu electrodes were prepared in carbon Vulcan XC72R through the reduction method and applied as electrocatalysts in ethanol ox
J. Braz. Chem. Soc.. Publicado em: 2018-08
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7. CO Tolerance and Stability of Proton Exchange Membrane Fuel Cells with Nafion® and Aquivion® Membranes and Mo-Based Anode Electrocatalysts
This work presents a CO tolerance study of PtMo/C (70:30, Pt:Mo) and Pt/MoO2-C anode catalysts on proton exchange membrane fuel cells (PEMFC) with Nafion® and Aquivion® ionomer membranes. Results denote improved activity for the hydrogen oxidation reaction (HOR) in the presence of CO on both anode catalysts at 85 ºC. Experiments of identical location tran
J. Braz. Chem. Soc.. Publicado em: 2018-05
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8. The Effect of Electrolyte pH on the Ni-Co Mixed Oxides Coatings Produced from Citrate Baths
In this work, Ni-Co oxides coatings were produced using electrochemical techniques (chronopotentiometry and/or linear voltammetry) and solutions containing Ni2+ and Co2+ ions in the molar ratio 1: 2, sodium citrate as the ligand, and different pH values (7.5 and 10.5). Energy dispersive spectrometry (EDS), scanning electron microscopy (SEM), Raman spectrosco
Mat. Res.. Publicado em: 11/01/2018
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9. Investigation of Electrocatalysts for Selective Reduction of CO2 to CO: Monitoring the Reaction Products by on line Mass Spectrometry and Gas Chromatography
The carbon dioxide electrocatalytic reduction is central for the development of regenerative cycles of electrochemical energy conversion and storage. Herein, the gaseous products of the CO2 electroreduction were monitored by using an electrochemical cell on line coupled to a differential electrochemical mass spectrometer (DEMS), aiming at searching for elect
J. Braz. Chem. Soc.. Publicado em: 2017-09
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10. Ethylene glycol oxidation on ternary PtRhNi/C electrocatalyst with different metal compositions
ABSTRACT Direct Alcohol Fuel Cells (DAFC’s) are an alternative to fuel cell systems and when is used alkaline medium this has an increase performance. The alkaline direct alcohol fuel cells (ADAFC's) have some advantages such as low-emission, high energy efficiency, improved oxidation kinetics, low crossover and in addition there is a broad range of materi
Matéria (Rio J.). Publicado em: 20/07/2017
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11. Electrooxidation of Mixed Ethanol and Methanol Solutions on PtSn/C Electrocatalysts Prepared by the Polymeric Precursor Method
Different mass ratio proportions of PtSn (m/m) electrocatalysts with 20% metal loading on a carbon support were prepared for use in ethanol:methanol solutions oxidation reactions. PtSn/C (3:1) (91% alloy degree, lattice parameter of 0.399 nm and mean crystallite size 4.8 nm) presented the best activity for oxidation of mixed solutions. The highest normalized
J. Braz. Chem. Soc.. Publicado em: 2017-06
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12. Metal Oxide/Gold Hybrid Nanocomposites as Electrocatalysts for Alkaline Air Electrodes
MnCo2O4/Au was investigated as an electrocatalyst for the oxygen reduction and evolution in alkaline media. Polarization curves showed an unprecedented activity for the oxygen reduction due to a synergistic effect between MnCo2O4 and Au, involving CoII/CoIII-MnIII/MnIV, as revealed by in situ X-ray absorption near edge structure (XANES). Additionally, result
J. Braz. Chem. Soc.. Publicado em: 2015-11