Hostname: page-component-7479d7b7d-rvbq7 Total loading time: 0 Render date: 2024-07-11T12:47:12.488Z Has data issue: false hasContentIssue false

Preparation and Powder Characteristics of LNF Compounds for Application in SOFCs

Published online by Cambridge University Press:  13 March 2015

Bruna N. Ramirez
Affiliation:
Universidade Federal do ABC, Av. dos Estados, 5001 – Bangu, Santo André - SP, Brasil.
Fábio C. Fonseca
Affiliation:
Instituto de Pesquisas Energéticas e Nucleares, Av. L.Prestes 2242- Cid. Univ.- SP- Brasil
Márcia T. Escote
Affiliation:
Universidade Federal do ABC, Av. dos Estados, 5001 – Bangu, Santo André - SP, Brasil.
Get access

Abstract

LaNi(1-x)FexO3 (LNF) compounds, with 0.0 ≤ x ≤ 0.4, have interesting physical properties such as high ionic and electronic conductivity, good catalytic activity for oxygen reduction, and thermodynamic compatibility with the YSZ electrolyte, which makes them potential candidates for SOFCs (solid oxides fuel cells) cathodes. Order for these excellent properties are achieved, it is necessary to ensure the presence of the homogeneous phase LNF. The methods for preparing these compounds influence the formation and stabilization of the homogeneous phase and therefore the physical properties of these oxides. For this reason, this work deals with the synthesis of the family of compounds LNF and the correlation between the synthesis and the physical properties obtained. In this context, LNF compounds were synthesized by a modified Pechini method for production of powders. Two different synthetic routes were employed, changing the source of nickel: nickel acetate and nickel nitrate. In order to study the thermal evolution of the LNF phase in these compounds, thermal analysis (DTG) and X-ray diffraction (XRD) were performed. The XRD was verified that the series of compounds synthesized by nickel acetate originated monophasic samples different from those obtained with nickel nitrate. We studied the influence of time and sintering temperature on the superficial characteristics of the samples and it was observed the reduction in sintering time allowed obtaining powders of perovskite phase, with grain sizes and smaller clusters than what was observed in the compound -treated for 10 h. To characterize the particle size, the powders were characterized by curves absorption/desorption (BET). The results also show that heat treatment for shorter times resulted in decreased particle size as well as increase the surface area of the compounds.

Type
Articles
Copyright
Copyright © Materials Research Society 2015 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

BEVILACQUA, M. et al. . Preparation, Characterization, and Electrochemical Properties of Pure and Composite LaNi 0.6 Fe 0.4 O 3 -Based Cathodes for IT-SOFC. Chemistry of Materials, v. 19, n. 24, p. 59265936, nov. 2007.CrossRefGoogle Scholar
SWIERCZEK, K. et al. . LFN and LSCFN perovskites — structure and transport properties. Solid State Ionics, v. 177, n. 19-25, p. 18111817, 15 out. 2006.CrossRefGoogle Scholar
BRUNAUER, S.; EMMETT, P. H.; TELLER, E. Adsorption of Gases in Multimolecular Layers. Journal of the American Chemical Society, v. 407, n. 1, p. 309319, 1938.CrossRefGoogle Scholar
ARANDIYAN, H. et al. . Methane reforming to syngas over LaNixFe1−xO3 (0≤x≤1) mixed-oxide perovskites in the presence of CO2 and O2. Journal of Industrial and Engineering Chemistry, v. 18, n. 6, p. 21032114, nov. 2012.CrossRefGoogle Scholar
NIWA, E. et al. . Conductivity and sintering property of LaNi1−xFexO3 ceramics prepared by Pechini method. Solid State Ionics, v. 201, n. 1, p. 8793, out. 2011.CrossRefGoogle Scholar
NIWA, E.; UEMATSU, C.; HASHIMOTO, T. Sintering temperature dependence of conductivity, porosity and specific surface area of LaNi0.6Fe0.4O3 ceramics as cathode material for solid oxide fuel cells—Superiority of Pechini method among various solution mixing processes. Materials Research Bulletin, v. 48, n. 1, p. 16, jan. 2013.CrossRefGoogle Scholar