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

Thomas Y George; Tristan Asset; Arezoo Avid; Plamen Atanassov; Iryna V Zenyuk

doi:10.1002/cphc.201901091

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

Chemphyschem. 2020 Mar 17;21(6):469-475. doi: 10.1002/cphc.201901091. Epub 2020 Feb 4.

Authors

Thomas Y George¹, Tristan Asset^{2

3}, Arezoo Avid^{2

3}, Plamen Atanassov^{2

3}, Iryna V Zenyuk^{2

3}

Affiliations

¹ Department of Chemical and Biological Engineering, Tufts University, Medford, MA, USA.
² Department of Chemical and Biomolecular Engineering, University of California Irvine, Irvine, CA, USA.
³ National Fuel Cell Research Center, University of California Irvine, Irvine, CA, USA.

PMID: 31945252
DOI: 10.1002/cphc.201901091

Abstract

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.

Keywords: PEM fuel cells; kinetic isotope effect; oxygen reduction reaction; platinum; rate-determining step.

Publication types

Research Support, Non-U.S. Gov't

Abstract

Publication types

Grants and funding