Download PDF
Research Highlight  |  Open Access  |  11 Nov 2024

Oxygen coverage effect promotes oxygen evolution reaction

Views: 104 |  Downloads: 19 |  Cited:  0
Chem Synth 2024;4:71.
10.20517/cs.2024.123 |  © The Author(s) 2024.
Author Information
Article Notes
Cite This Article

Keywords

Iridium-based electrocatalysts, oxygen coverage, oxygen evolution reaction

Green hydrogen production powered by water electrolysis stands as a promising technology for renewable energy transition and storage. However, oxygen evolution reaction (OER) with sluggish multi-electron-transferred process has limited the overall efficiency of water splitting. For iridium-based benchmark materials, understanding the intrinsic water oxidation kinetics and realizing accurate activity descriptors are key factors to help design better electrocatalysts for practical application of water electrolysis.

Recently reported in Nature Catalysis, through clever analysis of the absorption spectra in operando time-resolved ultraviolet-visible (UV-vis) spectroscopy, Liang et al. have quantified the active site density and oxygen binding strengths on different iridium oxides, unveiling the effect of adsorbate-adsorbate interactions on O–O bond formation[1]. Previously, for rational design of OER catalysts, oxygen adsorption energy (ΔG*O) was first introduced by Rossmeisl and Nørskov et al. to describe the OER activity[2,3], and the standard free energy change ΔG*O0 - ΔG*OH0 was universally applied as the activity descriptor with a volcano-type relationship[4-6]. In this work, besides the conventional binding energetics of ΔG*O0 - ΔG*OH0, an additional oxygen coverage effect showed how the interactions between adsorbates can control the OER kinetics [Figure 1A]. A clever modification of the conventional activity descriptor was made, as shown in the improved three-dimensional volcano plot [Figure 1B]. Accordingly, the previous descriptor ΔG*O0 - ΔG*OH0 was deconvoluted into: (1) the intermediate binding strength without oxygen coverage [ΔG*O0 - ΔG*OH0(θ*O = 0)], and (2) the interaction strength between adsorbates [ΔG*O0 - ΔG*OH0 (θ*O = 0) + *O]. Thereby, an optimized catalyst design could be directed by balancing the two opposing effects. Thus, the conventional optimal binding energetics can be broken by increasing the oxygen coverage in the case of over-strong *O binding at active sites.

Oxygen coverage effect promotes oxygen evolution reaction

Figure 1. (A) Experimentally determined ΔG*O0 - ΔG*OH0 values at different oxygen coverages; (B) Effects of the *O interaction strength and *O binding strength on the OER activity. Reproduced with permission[1]; (C) Schematic illustration of oxygen coverage effect on atomic grid structure toward accelerated O–O bond formation; (D and E) Atomic-resolution high-angle annular dark field scanning transmission electron microscopy image of atomic grid structure on Ir-Mn-Ov catalyst and the corresponding three-dimensional surface plot with atom-overlapping. Reproduced with permission[7].

Our recent work has also demonstrated the oxygen coverage effect to promote O–O bond formation during the OER process [Figure 1C][7]. A new metal-support configuration of dense atomic grids was constructed through high-density Ir sites (~10 atoms per nm2) supported on MnO2-x [Figure 1D and E]. Initial Mn-Ov coordination defects in MnO2-x give rise to electrochemical generation of enriched oxygen coverage as probed by the increased Mn-O coordination intensity under OER potentials from operando X-ray absorption fine structure (XAFS) spectra. Moreover, the Ir grid lines proceed with highly electrophilic nature of Ir–O(II-δ)- bonds during OER, facilitating oxygen radicals on Ir sites directly coupling with the rich oxygen adsorbates on support Mn sites. Thereby, an ultra-low OER overpotential of 166 mV at 10 mA·cm-2 and a striking mass activity which was 380 times higher than commercial IrO2 were achieved on this catalyst. The oxygen coverage effect also conforms to the practical operation at an oxygen-enriched environment on the anode side of the proton exchange membrane water electrolyzer, which leads to a low cell voltage of 1.58 V to reach the current density of 1 A·cm-2.

In summary, the oxygen coverage effect can be complementary to the conventional binding energetics. Based on this insight, future active OER catalysts can be predicted and designed far beyond the current models. Those non-precious metal-based materials, which have not been considered as promising catalysts owing to inappropriate oxygen binding strength, could be activated by optimizing oxygen coverage through crystallinity design, defect engineering, porosification treatment, and so on. Moreover, OER pathways, including enriched oxygen coverage-induced oxygen pathway mechanism (OPM), can be considered to overcome the scaling relationship between the intermediates[7]. Conventional lattice oxygen mechanism (LOM) can also be modified with high oxygen coverage, which aids in replenishing the surface oxygen vacancies that resulted from lattice oxygen oxidation and avoids structural collapse[8]. Furthermore, for impure water electrolysis such as seawater electrolysis, the oxygen coverage effect can also act as a powerful handle to prevent Cl- binding and aids the exclusive selectivity toward OER.

DECLARATIONS

Authors’ contributions

Wrote the draft manuscript: Lin H

Revised and rewrote some parts of the manuscript: Liu P, Yang H

Availability of data and materials

Not applicable.

Financial support and sponsorship

This work was financially supported by the National Natural Science Foundation of China (22239001) and the Shanghai Pilot Program for Basic Research (22TQ1400100-12).

Conflicts of interest

Liu P is a Junior Editorial Board Member of the journal Chemical Synthesis, while the other authors have declared that they have no conflicts of interest.

Ethical approval and consent to participate

Not applicable.

Consent for publication

Not applicable.

Copyright

© The Author(s) 2024.

REFERENCES

1. Liang C, Rao RR, Svane KL, et al. Unravelling the effects of active site density and energetics on the water oxidation activity of iridium oxides. Nat Catal 2024;7:763-75.

2. Rossmeisl J, Qu ZW, Zhu H, Kroes GJ, Nørskov JK. Electrolysis of water on oxide surfaces. J Electroanal Chem 2007;607:83-9.

3. Rossmeisl J, Logadottir A, Nørskov JK. Electrolysis of water on (oxidized) metal surfaces. Chem Phys 2005;319:178-84.

4. Gloag L, Somerville SV, Gooding JJ, Tilley RD. Co-catalytic metal–support interactions in single-atom electrocatalysts. Nat Rev Mater 2024;9:173-89.

5. Deng L, Hung SF, Lin ZY, et al. Valence oscillation of Ru active sites for efficient and robust acidic water oxidation. Adv Mater 2023;35:e2305939.

6. Oener SZ, Bergmann A, Cuenya BR. Designing active oxides for a durable oxygen evolution reaction. Nat Synth 2023;2:817-27.

7. Lin HY, Yang QQ, Lin MY, et al. Enriched oxygen coverage localized within Ir atomic grids for enhanced oxygen evolution electrocatalysis. Adv Mater 2024;36:e2408045.

8. Gou W, Zhang S, Wang Y, et al. Oxygen spillover from RuO2 to MoO3 enhances the activity and durability of RuO2 for acidic oxygen evolution. Energy Environ Sci 2024;17:6755-65.

Cite This Article

Research Highlight
Open Access
Oxygen coverage effect promotes oxygen evolution reaction
Haoyang Lin, ... Huagui Yang

How to Cite

Lin, H.; Liu, P.; Yang, H. Oxygen coverage effect promotes oxygen evolution reaction. Chem. Synth. 2024, 4, 71. http://dx.doi.org/10.20517/cs.2024.123

Download Citation

If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click on download.

Export Citation File:

Type of Import

Tips on Downloading Citation

This feature enables you to download the bibliographic information (also called citation data, header data, or metadata) for the articles on our site.

Citation Manager File Format

Use the radio buttons to choose how to format the bibliographic data you're harvesting. Several citation manager formats are available, including EndNote and BibTex.

Type of Import

If you have citation management software installed on your computer your Web browser should be able to import metadata directly into your reference database.

Direct Import: When the Direct Import option is selected (the default state), a dialogue box will give you the option to Save or Open the downloaded citation data. Choosing Open will either launch your citation manager or give you a choice of applications with which to use the metadata. The Save option saves the file locally for later use.

Indirect Import: When the Indirect Import option is selected, the metadata is displayed and may be copied and pasted as needed.

About This Article

© The Author(s) 2024. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, sharing, adaptation, distribution and reproduction in any medium or format, for any purpose, even commercially, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Author Biographies

​Hao Yang Lin
Hao Yang Lin received his B.S. degree from East China University of Science and Technology (ECUST) in 2022. He is currently a Ph.D. candidate under the supervision of Prof. Hua Gui Yang in the School of Materials Science and Engineering at ECUST. His current research interests focus on the design of advanced nanomaterials for proton exchange membrane-based water electrolysis.
Peng Fei Liu
Peng Fei Liu received his B.S. and Ph.D. degrees from East China University of Science and Technology (ECUST) in 2013 and 2018, respectively, and then worked in Prof. Hua Gui Yang's group as a Postdoctoral Research Fellow. Since 2020, he has served as an Associate Research Fellow/Professor at ECUST. His current research interests involve the design and synthesis of inorganic functional materials with well-defined structures for electrocatalysis.
Hua Gui Yang
Prof. Hua Gui Yang received his Ph.D. degree from the National University of Singapore in 2005. He joined the University of Queensland in 2007 as a Postdoctoral Research Fellow. After completing his postdoctoral training, he returned to China and assumed a professorship at East China University of Science and Technology in late 2008. His main research interests lie in the rational design and fabrication of functional materials for solar fuels.

Data & Comments

Data

Views
104
Downloads
19
Citations
0
Comments
0
2

Comments

Comments must be written in English. Spam, offensive content, impersonation, and private information will not be permitted. If any comment is reported and identified as inappropriate content by OAE staff, the comment will be removed without notice. If you have any queries or need any help, please contact us at support@oaepublish.com.

0
Download PDF
Share This Article
Scan the QR code for reading!
See Updates
Contents
Figures
Related
Chemical Synthesis
ISSN 2769-5247 (Online)

Portico

All published articles are preserved here permanently:

https://www.portico.org/publishers/oae/

Portico

All published articles are preserved here permanently:

https://www.portico.org/publishers/oae/