Platinum surface oxides govern the cathodic overpotential of the oxygen reduction reaction

EES Catalysis 2026 Open access

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Authors: Alfred Larsson, Andrea Grespi, Ožbej Vodeb, Karen van den Akker, Auden Ti, Claire Berschauer, Alexandra Imre, Philip Miguel Kofoed, Estephanía Lira, Mahesh Ramakrishnan, Stuart Ansell, Justus Just
+7 more Henrik Grönbeck, Ulrike Diebold, E. Lundgren, L. R. Merte, Dušan Strmčnik, Rik V. Mom, Marc T. M. Koper
DOI: 10.1039/d6ey00014b
Cited by: 4
References: 57

Abstract

saturation. Furthermore, we show that the oxide coverage increases with upper vertex potential, slower scan rates, and extended hold times at OCP, illustrating how oxides inhibit ORR during fuel cell start-up. Crucially, we demonstrate that the ORR onset is delayed until these oxides are reduced, establishing a direct, negative relationship between oxide coverage and ORR activity. This reveals a revised mechanism in which the potential-determining step is the reduction of surface oxides, and the slow kinetics of this restructuring ultimately determine when surface sites become catalytically available.

Fields of Study & Subjects

Electrocatalysts for Energy Conversion Nanoporous metals and alloys Fuel Cells and Related Materials

Publication details

Journal / source
EES Catalysis
Publisher
Royal Society of Chemistry (RSC)
Volume
4
Issue
3
Pages
754–765
Publication date
1 January 2026
Language
EN