Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.



An in situ XAS study of high surface-area IrO2 produced by the polymeric precursor synthesis

Author affiliations

Abstract

Iridium oxide powders with a surface area of more than 1 m2 g−1 (4 m2 g−2 from the H-UPD charge) and iridium-oxide crystallites less than 10 nm across were synthesized by heat treating gels formed from citric acid, ethylene glycol and dihydrogen hexachloroiridate(IV) in air. The characteristics of the resulting material was found to be strongly dependent on the heat-treatment step in the synthesis. A single heat-treatment of the gel resulted in a material with a substantial fraction of elemental iridium metal, i.e. iridium in oxidation state zero (Ir0). Post-synthesis modification of the powder by potential cycling resulted in oxidation peaks consistent with the conversion of the metal phase to iridium oxide. Linear combination of the near-edge part of the X-ray absorption data (X-ray absorption near-edge spectroscopy, XANES) collected in situ during potential cycling and an analysis of the extended X-ray fine-structure (EXAFS) part of the spectrum showed that the overall metal fraction was not significantly affected by the cycling. The oxidation of the metal phase is therefore limited to a thin layer of oxide at the metal surface, and a significant part of the iridium is left inactive. A modification of the heat treatment procedure of the sample resulted in iridium oxide containing only insignificant amounts of elemental iridium metal.

Graphical abstract: An in situ XAS study of high surface-area IrO2 produced by the polymeric precursor synthesis

Back to tab navigation

Supplementary files

Article information


Submitted
14 Jan 2020
Accepted
27 Mar 2020
First published
30 Mar 2020

Phys. Chem. Chem. Phys., 2020, Advance Article
Article type
Paper

An in situ XAS study of high surface-area IrO2 produced by the polymeric precursor synthesis

A. H. Reksten, A. E. Russell, P. W. Richardson, S. J. Thompson, K. Mathisen, F. Seland and S. Sunde, Phys. Chem. Chem. Phys., 2020, Advance Article , DOI: 10.1039/D0CP00217H

Social activity

Search articles by author

Spotlight

Advertisements