Open AccessA High-Pressure System for Studying Oxygen Reduction During Pt Nanoparticle Collisions
Author(s) -
Yulun Zhang,
Donald A. Robinson,
Kim McKelvey,
Haixia Ren,
Henry S. White,
Martin A. Edwards
Publication year - 2020
Publication title -
journal of the electrochemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.258
H-Index - 271
eISSN - 1945-7111
pISSN - 0013-4651
DOI - 10.1149/1945-7111/abcde2
Subject(s) - radius , nanoparticle , particle (ecology) , electrode , atmospheric pressure , chemistry , analytical chemistry (journal) , particle number , oxygen , aerosol , particle size , catalysis , oxygen reduction reaction , electrochemistry , materials science , nanotechnology , thermodynamics , chromatography , physics , organic chemistry , oceanography , computer security , volume (thermodynamics) , geology , meteorology , computer science
Here we report measurements of the oxygen reduction reaction (ORR) at single Pt nanoparticles (NPs) through their collision with a Au microdisk electrode of lower electrocatalytic activity. Performing measurements at an elevated pressure (10-atm, pure O 2 ) raises the O 2 concentration ∼50-fold over air-saturated measurements, allowing the ORR activity of smaller Pt NPs to be resolved and quantified, compared to measurements taken at atmospheric pressure. Single-NP ORR current vs potential measurements for 2.6, 16, and 24 nm radius citrate-capped Pt NPs, show the catalytic activity of the smallest Pt NPs to be roughly one order of magnitude greater than the activity of the larger NPs. The particle-by-particle nature of our measurement quantifies the distribution of electrocatalytic activities of individual particles, which we determine to be larger than can be explained by the distribution of particle sizes. Additionally, we report that some of the observed ORR current transients contain multiple sharp peaks per single-NP measurement, indicating multiple collisions of a single Pt NP at the electrode surface.