Water-splitting electrocatalysis in acid conditions using ruthenate-iridate pyrochlores

DOI: 10.1002/anie.201406668
PMID: 25196322

Authors: Kripasindhu Sardar (University of Warwick) , Enrico Petrucco (Johnson Matthey Fuel Cells) , Craig Hiley (University of Warwick) , Jonathan D. B. Sharman (Johnson Matthey Technology Centre) , Peter Wells (Research Complex at Harwell) , Andrea Russell (University of Southampton) , Reza J. Kashtiban (University of Warwick) , Jeremy Sloan (University of Warwick) , Richard Walton (University of Warwick)
Co-authored by industrial partner: Yes

Type: Journal Paper
Journal: Angewandte Chemie International Edition , VOL 53 (41) , PAGES 10960 - 10964

State: Published (Approved)
Published: October 2014
Diamond Proposal Number(s): 7646

Abstract: The pyrochlore solid solution (Na0.33Ce0.67)2(Ir1−xRux)2O7 (0≤x≤1), containing B-site RuIV and IrIV is prepared by hydrothermal synthesis and used as a catalyst layer for electrochemical oxygen evolution from water at pH<7. The materials have atomically mixed Ru and Ir and their nanocrystalline form allows effective fabrication of electrode coatings with improved charge densities over a typical (Ru,Ir)O2 catalyst. An in situ study of the catalyst layers using XANES spectroscopy at the Ir LIII and Ru K edges shows that both Ru and Ir participate in redox chemistry at oxygen evolution conditions and that Ru is more active than Ir, being oxidized by almost one oxidation state at maximum applied potential, with no evidence for ruthenate or iridate in +6 or higher oxidation states.

Journal Keywords: Electrochemistry; Hydrothermal Synthesis; Iridium; Ruthenium; X-Ray Absorption Spectroscopy

Subject Areas: Chemistry, Materials, Energy


Instruments: B18-Core EXAFS

Added On: 30/09/2014 10:06

Documents:
10960_ftp.pdf

Discipline Tags:

Energy Physical Chemistry Catalysis Chemistry Materials Science

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS) X-ray Absorption Near Edge Structure (XANES)