Electrochemically induced oxygen spillover and diffusion on Pt(111): PEEM imaging and kinetic modelling

Eva Mutoro, Christian Hellwig, Bjoern Luerssen, Sebastian Guenther, Wolfgang G. Bessler, Jürgen Janek

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

Electrochemically induced oxygen spillover and diffusion in the Pt(O 2)YSZ system is investigated in a combined experimental and theoretical study. The spreading of spillover oxygen is imaged by photoelectron emission microscopy (PEEM) on dense and epitaxial Pt(111) thin film electrodes prepared by pulsed laser deposition (PLD). Two different models are used to obtain surface diffusion coefficients from the experimental data, (i) an analytical solution of Fick's 2nd law of diffusion, and (ii) a numerical reaction-diffusion model that includes recombinative desorption of O2 into the gas phase. The resulting diffusion coefficient has an activation energy of 50 kJ mol-1 and a preexponential factor of 0.129 cm 2 s-1 with an estimated uncertainty of ±20% for the activation energy and ±50% for the absolute value. The Fickian model slightly overpredicts diffusion coefficients due to the neglect of oxygen desorption. Experimental and theoretical results and limitations are discussed and compared to previous work.

Original languageEnglish
Pages (from-to)12798-12807
Number of pages10
JournalPhysical Chemistry Chemical Physics
Volume13
Issue number28
DOIs
StatePublished - 28 Jul 2011
Externally publishedYes

Fingerprint

Dive into the research topics of 'Electrochemically induced oxygen spillover and diffusion on Pt(111): PEEM imaging and kinetic modelling'. Together they form a unique fingerprint.

Cite this