TY - JOUR
T1 - Structural characterization of Pt-Pd core-shell nanoparticles by Cs-corrected STEM
AU - Esparza, R.
AU - García-Ruiz, Amado F.
AU - Velázquez Salazar, J. J.
AU - Pérez, R.
AU - José-Yacamán, M.
N1 - Funding Information:
Acknowledgments One of the authors, AFGR, wants to thank CONACYT-México for supporting his sabbatical stay at the UTSA. The authors acknowledge support from Welch: The Welch Foundation grant award # AX-1615; The National Science Foundation grant award # DMR-1103730; ‘‘Alloys at the Nanoscale: The Case of Nanoparticles’’ Second Phase; and NIH – RCMI: RCMI grant 5G12RR013646-12 Award Number 5G12RR013646-12 from the National Center For Research Resources.
PY - 2013/1
Y1 - 2013/1
N2 - 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.
AB - 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.
KW - Aberration corrected
KW - Chemical synthesis
KW - Core-shell
KW - Electron microscopy
KW - Nanostructure
KW - Pt-Pd
UR - http://www.scopus.com/inward/record.url?scp=84870168562&partnerID=8YFLogxK
U2 - 10.1007/s11051-012-1342-2
DO - 10.1007/s11051-012-1342-2
M3 - Artículo
SN - 1388-0764
VL - 15
JO - Journal of Nanoparticle Research
JF - Journal of Nanoparticle Research
IS - 1
M1 - 1342
ER -