In situ electrochemical X-ray absorption spectroscopy of oxygen reduction electrocatalysis with high oxygen flux

Evan M Erickson; Matthew S Thorum; Relja Vasić; Nebojša S Marinković; Anatoly I Frenkel; Andrew A Gewirth; Ralph G Nuzzo

doi:10.1021/ja210465x

In situ electrochemical X-ray absorption spectroscopy of oxygen reduction electrocatalysis with high oxygen flux

J Am Chem Soc. 2012 Jan 11;134(1):197-200. doi: 10.1021/ja210465x. Epub 2011 Dec 21.

Authors

Evan M Erickson¹, Matthew S Thorum, Relja Vasić, Nebojša S Marinković, Anatoly I Frenkel, Andrew A Gewirth, Ralph G Nuzzo

Affiliation

¹ Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.

PMID: 22188603
DOI: 10.1021/ja210465x

Abstract

An in situ electrochemical X-ray absorption spectroscopy (XAS) cell has been fabricated that enables high oxygen flux to the working electrode by utilizing a thin poly(dimethylsiloxane) (PDMS) window. This cell design enables in situ XAS investigations of the oxygen reduction reaction (ORR) at high operating current densities greater than 1 mA in an oxygen-purged environment. When the cell was used to study the ORR for a Pt on carbon electrocatalyst, the data revealed a progressive evolution of the electronic structure of the metal clusters that is both potential-dependent and strongly current-dependent. The trends establish a direct correlation to d-state occupancies that directly tracks the character of the Pt-O bonding present.