Issue 8, 2015

An efficiently tuned d-orbital occupation of IrO2 by doping with Cu for enhancing the oxygen evolution reaction activity

Abstract

The oxygen evolution reaction (OER) has been regarded as a key half reaction for energy conversion technologies and requires high energy to create O[double bond, length as m-dash]O bonds. Transition metal oxides (TMOs) seem to be a promising and appealing solution to the challenge because of the diversity of their d-orbital states. We chose IrO2 as a model because it is universally accepted as a current state-of-the-art OER catalyst. In this study, copper-doped IrO2, particularly Cu0.3Ir0.7Oδ, is shown to significantly improve the OER activity in acidic, neutral and basic solutions compared to un-doped IrO2. The substituted amount of Cu in IrO2 has a limit described by the Cu0.3Ir0.7Oδ composition. We determined that the performance of Cu0.3Ir0.7Oδ is due primarily to an increase in the Jahn–Teller effect in the CuO6 octahedra, and partially to oxygen defects in the lattice induced by the IrO6 octahedral geometric structure distortions, which enhance the lift degeneracy of the t2g and eg orbitals, making the dz2 orbital partially occupied. This phenomenon efficiently reduces the difference between ΔG2 and ΔG3 in the free energy from the density functional theoretical (DFT) calculations and can yield a lower theoretical overpotential comparable to that of IrO2. The proposed method of doping with foreign elements to tune the electron occupation between the t2g and eg orbital states of Ir creates an opportunity for designing effective OER catalysts using the TMO groups.

Graphical abstract: An efficiently tuned d-orbital occupation of IrO2 by doping with Cu for enhancing the oxygen evolution reaction activity

Supplementary files

Article information

Article type
Edge Article
Submitted
08 abr 2015
Accepted
12 jun 2015
First published
12 jun 2015
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY-NC license

Chem. Sci., 2015,6, 4993-4999

Author version available

An efficiently tuned d-orbital occupation of IrO2 by doping with Cu for enhancing the oxygen evolution reaction activity

W. Sun, Y. Song, X. Gong, L. Cao and J. Yang, Chem. Sci., 2015, 6, 4993 DOI: 10.1039/C5SC01251A

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements