TY - JOUR
T1 - Tailoring the Oxygen Reduction Activity of Pt Nanoparticles through Surface Defects
T2 - A Simple Top-Down Approach
AU - Fichtner, Johannes
AU - Watzele, Sebastian
AU - Garlyyev, Batyr
AU - Kluge, Regina M.
AU - Haimerl, Felix
AU - El-Sayed, Hany A.
AU - Li, Wei Jin
AU - Maillard, Frédéric M.
AU - Dubau, Laetitia
AU - Chattot, Raphaël
AU - Michalička, Jan
AU - MacAk, Jan M.
AU - Wang, Wu
AU - Wang, Di
AU - Gigl, Thomas
AU - Hugenschmidt, Christoph
AU - Bandarenka, Aliaksandr S.
N1 - Publisher Copyright:
Copyright © 2020 American Chemical Society.
PY - 2020/3/6
Y1 - 2020/3/6
N2 - Results from Pt model catalyst surfaces have demonstrated that surface defects, in particular surface concavities, can improve the oxygen reduction reaction (ORR) kinetics. It is, however, a challenging task to synthesize nanostructured catalysts with such defective surfaces. Hence, we present a one-step and upscalable top-down approach to produce a Pt/C catalyst (with 3 nm Pt nanoparticle diameter). Using high-resolution transmission electron microscopy and tomography, electrochemical techniques, high-energy X-ray measurements, and positron annihilation spectroscopy, we provide evidence of a high density of surface defects (including surface concavities). The ORR activity of the developed catalyst exceeds that of a commercial Pt/C catalyst, at least 2.7 times in terms of specific activity (1.62 mA/cm2 Pt at 0.9 V vs the reversible hydrogen electrode) and at least 1.7 times in terms of mass activity (712 mA/mgPt), which can be correlated to the enhanced amount of surface defects. In addition, the technique used here reduces the complexity of the synthesis (and therefore production costs) in comparison to state of the art bottom-up techniques.
AB - Results from Pt model catalyst surfaces have demonstrated that surface defects, in particular surface concavities, can improve the oxygen reduction reaction (ORR) kinetics. It is, however, a challenging task to synthesize nanostructured catalysts with such defective surfaces. Hence, we present a one-step and upscalable top-down approach to produce a Pt/C catalyst (with 3 nm Pt nanoparticle diameter). Using high-resolution transmission electron microscopy and tomography, electrochemical techniques, high-energy X-ray measurements, and positron annihilation spectroscopy, we provide evidence of a high density of surface defects (including surface concavities). The ORR activity of the developed catalyst exceeds that of a commercial Pt/C catalyst, at least 2.7 times in terms of specific activity (1.62 mA/cm2 Pt at 0.9 V vs the reversible hydrogen electrode) and at least 1.7 times in terms of mass activity (712 mA/mgPt), which can be correlated to the enhanced amount of surface defects. In addition, the technique used here reduces the complexity of the synthesis (and therefore production costs) in comparison to state of the art bottom-up techniques.
KW - electrocatalysis
KW - fuel cell
KW - oxygen reduction
KW - platinum nanoparticles
KW - top-down synthesis
UR - http://www.scopus.com/inward/record.url?scp=85080077162&partnerID=8YFLogxK
U2 - 10.1021/acscatal.9b04974
DO - 10.1021/acscatal.9b04974
M3 - Article
AN - SCOPUS:85080077162
SN - 2155-5435
VL - 10
SP - 3131
EP - 3142
JO - ACS Catalysis
JF - ACS Catalysis
IS - 5
ER -