Premium
Kinetic Isotope Effect as a Tool To Investigate the Oxygen Reduction Reaction on Pt‐based Electrocatalysts – Part I: High‐loading Pt/C and Pt Extended Surface
Author(s) -
George Thomas Y.,
Asset Tristan,
Avid Arezoo,
Atanassov Plamen,
Zenyuk Iryna V.
Publication year - 2020
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201901091
Subject(s) - kinetic isotope effect , chemistry , tafel equation , electrocatalyst , perchloric acid , platinum , inorganic chemistry , electrolyte , protonation , rate determining step , kinetics , sulfuric acid , reaction rate , deuterium , electrochemistry , catalysis , electrode , organic chemistry , ion , physics , quantum mechanics
Kinetic isotope effect (KIE) was used to study the rate‐determining step for oxygen reduction reaction (ORR) on dispersed Pt/C electrocatalyst and polycrystalline Pt (Pt‐poly). KIE is defined as the ratio of the kinetic current measured in protonated electrolyte versus deuterated electrolyte, with KIE values larger than one indicating proton participation in the rate‐determining step. The effect of poisoning anions on the platinum rate determining step is investigated by assessing the KIE in perchloric (non‐poisoning) and sulfuric acid‐based electrolytes. The kinetics currents were calculated using the Koutechy‐Levich and Tafel analysis. A KIE of 1 was observed for Pt/C (with a 40 wt.% Pt loading) and Pt‐poly, thus indicating that, on 40 wt. % Pt/C and Pt‐poly, the rate determining step is proton independent.