title: Identical Location Transmission Electron Microscopy Imaging of Site-Selective Pt Nanocatalysts: Electrochemical Activation and Surface Disordering.
abstract: We have employed identical location transmission electron microscopy (IL-TEM) to study changes in the shape and morphology of faceted Pt nanoparticles as a result of electrochemical cycling; a procedure typically employed for activating platinum surfaces. We find that the shape and morphology of the as-prepared hexagonal nanoparticles are rapidly degraded as a result of potential cycling up to +1.3 V. As few as 25 potential cycles are sufficient to cause significant degradation, and after about 500-1000 cycles the particles are dramatically degraded. We also see clear evidence of particle migration during potential cycling. These finding suggest that great care must be exercised in the use and study of shaped Pt nanoparticles (and related systems) as electrocatlysts, especially for the oxygen reduction reaction where high positive potentials are typically employed.
authors.affiliation: Instituto de Electroquímica, Universidad de Alicante . Apdo 99, 03080, Alicante, Spain.
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Arán-Ais
authors.forename: Yingchao
authors.initials: Y
authors.lastname: Yu
authors.forename: Robert
authors.initials: R
authors.lastname: Hovden
authors.affiliation: Instituto de Electroquímica, Universidad de Alicante . Apdo 99, 03080, Alicante, Spain.
authors.forename: Jose
authors.initials: J
authors.lastname: Solla-Gullón
authors.affiliation: Instituto de Electroquímica, Universidad de Alicante . Apdo 99, 03080, Alicante, Spain.
authors.forename: Enrique
authors.initials: E
authors.lastname: Herrero
authors.affiliation: Instituto de Electroquímica, Universidad de Alicante . Apdo 99, 03080, Alicante, Spain.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Feliu
authors.forename: Héctor D
authors.initials: HD
authors.lastname: Abruña