Lithium-directed transformation of amorphous iridium (oxy)hydroxides to produce active water oxidation catalysts

DOI: 10.1021/jacs.2c13567

Authors: Jonathan Ruiz Esquius (Cardiff University; International Iberian Nanotechnology Laboratory) , David J. Morgan (Cardiff University) , Gerardo Algara Siller (Fritz Haber-Institut der Max-Planck-Gesellschaft) , Diego Gianolio (Diamond Light Source) , Matteo Aramini (Diamond Light Source) , Leopold Lahn (Helmholtz-Zentrum Berlin; Friedrich-Alexander-Universität Erlangen-Nürnberg) , Olga Kasian (Helmholtz-Zentrum Berlin; Friedrich-Alexander-Universität Erlangen-Nürnberg) , Simon A. Kondrat (Loughborough University) , Robert Schlögl (Fritz Haber-Institut der Max-Planck-Gesellschaft; Max Planck Institute for Chemical Energy Conversion) , Graham J. Hutchings (Cardiff University) , Rosa Arrigo (University of Salford) , Simon J. Freakley (University of Bath)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of The American Chemical Society

State: Published (Approved)
Published: March 2023
Diamond Proposal Number(s): 15151

Abstract: The oxygen evolution reaction (OER) is crucial to future energy systems based on water electrolysis. Iridium oxides are promising catalysts due to their resistance to corrosion under acidic and oxidizing conditions. Highly active iridium (oxy)hydroxides prepared using alkali metal bases transform into low activity rutile IrO2 at elevated temperatures (>350 °C) during catalyst/electrode preparation. Depending on the residual amount of alkali metals, we now show that this transformation can result in either rutile IrO2 or nano-crystalline Li-intercalated IrOx. While the transition to rutile results in poor activity, the Li-intercalated IrOx has comparative activity and improved stability when compared to the highly active amorphous material despite being treated at 500 °C. This highly active nanocrystalline form of lithium iridate could be more resistant to industrial procedures to produce PEM membranes and provide a route to stabilize the high populations of redox active sites of amorphous iridium (oxy)hydroxides.

Subject Areas: Chemistry


Instruments: B18-Core EXAFS

Added On: 12/03/2023 20:45

Documents:
jacs.2c13567.pdf

Discipline Tags:

Physical Chemistry Catalysis Chemistry

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS)