TY - JOUR
T1 - Palladium local structure of La1-xSrxCo1-yFey-0.03Pd0.03O3-δperovskites synthesized using a one pot citrate method
AU - Martorana, Antonino
AU - Puleo, Fabrizio
AU - Parola, Valeria La
AU - Martorana, Antonino
AU - Longo, Alessandro
AU - Liotta, Leonarda F.
AU - Banerjee, Dipanjan
AU - Longo, Alessandro
AU - Liotta, Leonarda Francesca
AU - La Parola, Valeria
PY - 2014
Y1 - 2014
N2 - Nanostructured La1-xSrxCo1-yFey-0.03Pd0.03O3-δ(LSCF-Pd) perovskites with fixed La-Sr composition (x = 0.4) and two different Fe contents (y = 0.2 and 0.8) were successfully synthesized using a one pot citrate method starting from nitrates of the metal cations. Pd-free La1-xSrxCo1-yFeyO3-δ(LSCF) systems were prepared for comparison. LSCF powders were calcined at 1300 °C and characterized by XRD and Rietveld refinement, EXAFS, XPS, TPR analyses. Promotion of La0.6Sr0.4Co0.8Fe0.2O3-δand of La0.6Sr0.4Co0.2Fe0.8O3-δby incorporation of palladium was evidenced by solving the local environment of Pd using EXAFS spectroscopy. XPS analyses, in agreement with TPR measurements, demonstrated an increase of superficial oxygen vacancies, the variation being much more pronounced in the La0.6Sr0.4Co0.8Fe0.17Pd0.03O3-δsample. It is argued that this increase is associated with the introduction of Pd in the B site of LSCF. Moreover, ionic Pd4+was detected as the only palladium species on the perovskite surface, whereas Pd metal clusters of about 2 nm, not detectable in the surface, are embedded in the matrix and strongly interact with the bulk. This result has strong consequences in the synthesis and in the design of new perovskite materials that can be used as cathodes in fuel cell application at intermediate operating temperatures. © the Partner Organisations 2014.
AB - Nanostructured La1-xSrxCo1-yFey-0.03Pd0.03O3-δ(LSCF-Pd) perovskites with fixed La-Sr composition (x = 0.4) and two different Fe contents (y = 0.2 and 0.8) were successfully synthesized using a one pot citrate method starting from nitrates of the metal cations. Pd-free La1-xSrxCo1-yFeyO3-δ(LSCF) systems were prepared for comparison. LSCF powders were calcined at 1300 °C and characterized by XRD and Rietveld refinement, EXAFS, XPS, TPR analyses. Promotion of La0.6Sr0.4Co0.8Fe0.2O3-δand of La0.6Sr0.4Co0.2Fe0.8O3-δby incorporation of palladium was evidenced by solving the local environment of Pd using EXAFS spectroscopy. XPS analyses, in agreement with TPR measurements, demonstrated an increase of superficial oxygen vacancies, the variation being much more pronounced in the La0.6Sr0.4Co0.8Fe0.17Pd0.03O3-δsample. It is argued that this increase is associated with the introduction of Pd in the B site of LSCF. Moreover, ionic Pd4+was detected as the only palladium species on the perovskite surface, whereas Pd metal clusters of about 2 nm, not detectable in the surface, are embedded in the matrix and strongly interact with the bulk. This result has strong consequences in the synthesis and in the design of new perovskite materials that can be used as cathodes in fuel cell application at intermediate operating temperatures. © the Partner Organisations 2014.
KW - Physical and Theoretical Chemistry
KW - Physics and Astronomy (all)
KW - Physical and Theoretical Chemistry
KW - Physics and Astronomy (all)
UR - http://hdl.handle.net/10447/278285
M3 - Article
SN - 1463-9076
VL - 16
SP - 22677
EP - 22686
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
ER -