Structural characterization of Pt-Pd core-shell nanoparticles by Cs-corrected STEM
Por:
Esparza R., García-Ruiz A.F., Salazar, JJV, Pérez R., José-Yacamán M.
Publicada:
1 ene 2013
Resumen:
Pt-Pd core-shell nanoparticles were synthesized using a modified polyol method. A thermal method under refluxing, carrying on the reaction up to 285 C, has been performed to reduce metallic salts using ethylene glycol as reducer and poly(N-vinyl-2-pyrrolidone) as protective reagent of the formed bimetallic nanoparticles. According to other works, this type of structure has been studied and utilized to successfully increase the catalytic properties of monometallic nanoparticles Pt or Pd. Core-shell bimetallic nanoparticles were structurally characterized using aberration-corrected scanning transmission electron microscopy (Cs-STEM) equipped with a high-angle annular dark field detector, energy-dispersive X-ray spectrometry (EDS), and electron energy-loss spectroscopy (EELS). The high-resolution elemental line scan and mappings were carried out using a combination of STEM-EDS and STEM-EELS. The obtained results show the growth of the Pd shell on the Pt core with polyhedral morphology. The average size of the bimetallic nanoparticles was 13.5 nm and the average size of the core was 8.5 nm; consequently, the thickness of the shell was around 2.5 nm. The growth of the Pd shell on the Pt core is layer by layer, suggesting a Frank-van der Merwe growth mechanism. © 2012 Springer Science+Business Media Dordrecht.
Filiaciones:
Esparza R.:
Univ Nacl Autonoma Mexico, Ctr Fis Aplicada & Tecnol Avanzada, Santiago De Queretaro 76230, Queretaro, Mexico
García-Ruiz A.F.:
UPIICSA-COFAA, Instituto Politécnico Nacional, Te 950, Col. Granjas-México, Iztacalco, 08400 Mexico, D.F., Mexico
Department of Physics and Astronomy, University of Texas at San Antonio One UTSA Circle, San Antonio, TX 78249, United States
Pérez R.:
Univ Nacl Autonoma Mexico, Ctr Fis Aplicada & Tecnol Avanzada, Santiago De Queretaro 76230, Queretaro, Mexico
José-Yacamán M.:
Department of Physics and Astronomy, University of Texas at San Antonio One UTSA Circle, San Antonio, TX 78249, United States
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