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Stability of LaNiO3 gas diffusion oxygen electrodes
Silva, R. A.; Soares, C. O.; Carvalho, M. D.; Rangel, C. M.; Pereira, M. I. da SilvaIn this work LaNiO3 perovskite-type oxide, prepared by a self-combustion method, was optimized for activity and stability as an anode material for water electrolysis. A full electrochemical study was conducted in order to kinetically characterize electrodes prepared using carbon paper as a base for porous gas-diffusion electrodes in alkaline media, regarding water oxidation and oxygen reduction reactions at roo...
Enhanced bifunctional activity of LaNiO3-based gas diffusion electrodes for reg...
Silva, R. A.; Soares, C. O.; Carvalho, M. D.; Rangel, C. M.; Pereira, M. I. da SilvaPerovskites are of great interest when searching replacements for precious metals as catalyst for bifunctional oxygen electrodes involving the oxygen evolution(OER) and oxygen reduction reaction (ORR) as is the case of regenerative fuel cells. In this work a full electrochemical study on the electrochemical properties of gas diffusion electrodes (GDEs) using LaNiO3-based catalysts, conducted in alkaline media, ...
Assessing cell polarity reversal degradation phenomena in PEM fuel cells by ele...
Travassos, Maria Antónia; Lopes, Vitor V.; Silva, R. A.; Novais, Augusto Q.; Rangel, C. M.Electrochemical impedance spectroscopy (EIS) is identified as one of the most promising in-situ diagnostics tools available for assessing fuel cell ageing and degradation. In this work, the degradation phenomena caused by cell polarity reversal due to fuel starvation of an open cathode 16 membrane electrode assembly (MEA) – low power (PEM) fuel cell (15 W nominal power) – is reported using EIS as a base techni...
Oxide loading effect on the electrochemical performance of LaNiO3 coatings in a...
Soares, C. O.; Silva, R. A.; Carvalho, M. D.; Jorge, M. E. Melo; Gomes, A.; Rangel, C. M.LaNiO3 film electrodes were prepared by brush painting using nickel-foam supports in order to increase its surface area available for electrochemical reactions. Loadings varying between 20 and 140 mg cm-2 were tested. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to evaluate the coatings roughness (Rf) and morphology (f) factors, complemented by optical microscopy observat...
Towards stable bifunctional oxygen electrodes and corrosion resistant gas diffu...
Silva, R. A.; Soares, C. O.; Carvalho, M. D.; Jorge, M. E. Melo; Gomes, A.; Pereira, M. I. da Silva; Rangel, C. M.ABSTRACT: Regenerative fuel cells (RFCs) can provide very high energy storage at minimal weight in a dual mode system, by combining an electrolyzer and a fuel cell. Although RFCs are an appealing technology their development is still at an early stage. One key issue is the search for highly active electrocatalysts for both oxygen reduction and water oxidation. Presently, platinum is the best electrocatalyst for...
LaNiO3-based catalyst in gas diffusion electrodes: activity and stability for o...
Silva, R. A.; Soares, C. O.; Carvalho, M. D.; Jorge, M. E. Melo; Gomes, A.; Rangel, C. M.; Pereira, M. I. da SilvaPerovskite-type oxides are potential catalysts for next generation of regenerative fuel cells. In particular, LaNiO3 has been recognised as one of the most promising oxygen electrodes. In this work LaNiO3 perovskite-type oxides, prepared by a self-combustion method [1, 2], have been used for the preparation of porous gas-diffusion electrodes (GDE). Electrodes were prepared on Toray carbon paper (CP) substrates,...
Redox stability and bifunctionality of LaNiO3-based oxygen electrodes
Silva, R. A.; Soares, C. O.; Carvalho, M. D.; Jorge, M. E. Melo; Gomes, A.; Rangel, C. M.; Pereira, M. I. da SilvaOne key issue in the development of Regenerative fuel cells (RFCs) is the availability of cheap, highly active electrocatalysts for both oxygen reduction and water oxidation. Perovskite-type oxides, with the general formula ABO3, are potential catalysts for next generation of regenerative fuel cells. In particular, LaNiO3 has been recognised as one of the most promising oxygen electrodes. In this work LaNiO3 pe...
Characterization of MEA degradation for an open air cathode PEM fuel cell
Silva, R. A.; Hashimoto, T.; Thompson, G. E.; Rangel, C. M.As fuel cell technology matures and time scale to commercialization decreases, the need for a more comprehensive knowledge of materials’ aging mechanisms is essential to attain specified lifetime requirements for applications. In this work, the membrane electrode assembly (MEA) degradation of an eight-cell PEM low power stack was evaluated, during and after fuel cell aging in specified testing conditions of loa...
MEA degradation in PEM Fuel Cell : a joint SEM and TEM study
Silva, R. A.; Hashimoto, T.; Thompson, G. E.; Rangel, C. M.One of the important factors determining the lifetime of polymer electrolyte membrane fuel cells (PEMFCs) is membrane electrode assembly (MEA) degradation and failure. The lack of effective mitigation methods is largely due to the currently very limited understanding of the underlying mechanisms for mechanical and chemical degradations of fuel cell MEAs. This work reports on the effect of 1500 h operation of an...
Relaxation time distribution analysis of a polymer electrolyte fuel cell stack ...
Lopes, Vitor V.; Silva, R. A.; Novais, Augusto Q.; Rangel, C. M.Electrochemical impedance spectroscopy (EIS) is an analysis technique that is commonly used as a base diagnostics technique for the in-situ analysis of the kinetic and transport properties of proton exchange membrane (PEM) fuel cells. This work proposes to use the distribution of relaxation times (DRT) as a complementary analysis technique for the interpretation of EIS data. For this purpose, the DRT is deduced...
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