Temperature programmed oxygen desorption of the perovskites series Ln o.65Sro.3Mn0.8Co0.2O3 (Ln = La-Gd)

Tietz, F; Papadelis, Ch; Tsiplakides, D; Katsaounis, A; Vayenas, CG

dc.contributor.author	Tietz, F	en
dc.contributor.author	Papadelis, Ch	en
dc.contributor.author	Tsiplakides, D	en
dc.contributor.author	Katsaounis, A	en
dc.contributor.author	Vayenas, CG	en
dc.date.accessioned	2014-03-01T01:17:13Z
dc.date.available	2014-03-01T01:17:13Z
dc.date.issued	2001	en
dc.identifier.issn	09477047	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/14394
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-76549123611&partnerID=40&md5=4dddbfa8a34aa46f748492ff914973f6	en
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-76549123611&partnerID=40&md5=4dddbfa8a34aa46f748492ff914973f6	en
dc.title	Temperature programmed oxygen desorption of the perovskites series Ln o.65Sro.3Mn0.8Co0.2O3 (Ln = La-Gd)	en
heal.type	journalArticle	en
heal.publicationDate	2001	en
heal.abstract	Temperature programmed O2 desorption (hereafter denoted reduction, TPR) in a high vacuum system equipped with a mass spectrometer was used to investigate the oxygen loss as a function of temperature in perovskites materials of the type Ln0.65Sr0.3, Mn0.8Co 0.2O3 (Ln-La-Gd), which are important as potential electrode materials for solid oxide fuel cells (SOFC). The materials were prepared either by spray drying as described in [1] or via the Pechini method [2] for the perovskites with Ln = Nd-Gd. The TPR experiments were carried out at temperatures 300-1000 K with various heating rates ß in order to determine the onset of reduction and the activation energy of reduction for each perovskite. The experiments were carried out in an ultra high vacuum chamber (base pressure 10 -10mbar after baking) equipped with a quadrupole mass spectrometer [3, 4]. Additional oxygen adsorption was attempted at several adsorption temperatures but no discrete oxygen desorption peaks were observed before the onset of reduction. Pr0.65Sr0.3Mn 0.8Co0.2O3 was found to have the lowest reduction activation energy (149±19 kJ/mol) and the lowest temperature, TR, for onset of reduction (750 K). On the other hand Gd 0.65Sr0.3Mn0.8Co0.2O3 was found to have the highest reduction activation energy (232+38 kJ/mol) while the TR was about 850 K. The reduction activation energies follow the sequence Pr < Sm < Eu < La < Nd < Gd while the TR values follow the sequence Pr < La < Gd < Eu < Sm < Nd.	en
heal.journalName	Ionics	en
dc.identifier.volume	7	en
dc.identifier.issue	1-2	en
dc.identifier.spage	101	en
dc.identifier.epage	104	en