Defect-stabilized and oxygen-coordinated iron single-atom sites facilitate hydrogen peroxide electrosynthesis

Taotao Gao; Lu Qiu; Minghao Xie; Zhaoyu Jin; Panpan Li; Guihua Yu

doi:10.1039/d3mh00882g

Defect-stabilized and oxygen-coordinated iron single-atom sites facilitate hydrogen peroxide electrosynthesis

Mater Horiz. 2023 Oct 2;10(10):4270-4277. doi: 10.1039/d3mh00882g.

Authors

Taotao Gao^{1

2}, Lu Qiu^{2

3}, Minghao Xie⁴, Zhaoyu Jin⁵, Panpan Li¹, Guihua Yu⁴

Affiliations

¹ College of Materials Science and Engineering, Sichuan University, Chengdu, 610065, P. R. China. panpanli@scu.edu.cn.
² Institute for Advanced Study, Chengdu University, Chengdu, 610106, P. R. China.
³ College of Chemical Engineering, Sichuan University, Chengdu, 610065, P. R. China.
⁴ Materials Science and Engineering Program and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA. ghyu@austin.utexas.edu.
⁵ Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, 610054, P. R. China.

PMID: 37556212
DOI: 10.1039/d3mh00882g

Abstract

The selective two-electron electrochemical oxygen reduction reaction (ORR) for hydrogen peroxide (H₂O₂) production is a promising and green alternative method to the current energy-intensive anthraquinone process used in industry. In this study, we develop a single-atom catalyst (CNT-D-O-Fe) by anchoring defect-stabilized and oxygen-coordinated iron atomic sites (Fe-O₄) onto porous carbon nanotubes using a local etching strategy. Compared to O-doped CNTs with vacancy defects (CNT-D-O) and oxygen-coordinated Fe single-atom site modifying CNTs without a porous structure (CNT-O-Fe), CNT-D-O-Fe exhibits the highest H₂O₂ selectivity of 94.4% with a kinetic current density of 13.4 mA cm^-2. Fe-O₄ single-atom sites in the catalyst probably contribute to the intrinsic reactivity for the two-electron transfer process while vacancy defects greatly enhance the electrocatalytic stability. Theoretical calculations further support that the coordinated environment and defective moiety in CNT-D-O-Fe could efficiently optimize the adsorption strength of the *OOH intermediate over the Fe single atomic active sites. This contribution sheds light on the potential of defect-stabilized and oxygen-coordinated single-atom metal sites as a promising avenue for the rational design of highly efficient and selective catalysts towards various electrocatalytic reactions.