Spin-related symmetry breaking induced by half-disordered hybridization in BixEr2-xRu2O7 pyrochlores for acidic oxygen evolution

Gang Zhou; Peifang Wang; Bin Hu; Xinyue Shen; Chongchong Liu; Weixiang Tao; Peilin Huang; Lizhe Liu

doi:10.1038/s41467-022-31874-4

Spin-related symmetry breaking induced by half-disordered hybridization in Bi_xEr_2-xRu₂O₇ pyrochlores for acidic oxygen evolution

Nat Commun. 2022 Jul 15;13(1):4106. doi: 10.1038/s41467-022-31874-4.

Authors

Gang Zhou¹, Peifang Wang², Bin Hu¹, Xinyue Shen³, Chongchong Liu¹, Weixiang Tao¹, Peilin Huang¹, Lizhe Liu^{4

5}

Affiliations

¹ Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
² Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, People's Republic of China. pfwang2005@hhu.edu.cn.
³ College of Electronic and Optical Engineering, Nanjing University of Posts and Telecommunications, Nanjing, 210023, People's Republic of China.
⁴ Jiangsu Key Laboratory for Nanotechnology and Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructures, Nanjing University, Nanjing, 210093, People's Republic of China. lzliu@nju.edu.cn.
⁵ Guangxi Key Laboratory of Nuclear Physics and Nuclear Technology, Guangxi Normal University, Guilin, 514004, People's Republic of China. lzliu@nju.edu.cn.

Abstract

While acidic oxygen evolution reaction plays a critical role in electrochemical energy conversion devices, the sluggish reaction kinetics and poor stability in acidic electrolyte challenges materials development. Unlike traditional nano-structuring approaches, this work focuses on the structural symmetry breaking to rearrange spin electron occupation and optimize spin-dependent orbital interaction to alter charge transfer between catalysts and reactants. Herein, we propose an atomic half-disordering strategy in multistage-hybridized Bi_xEr_2-xRu₂O₇ pyrochlores to reconfigure orbital degeneracy and spin-related electron occupation. This strategy involves controlling the bonding interaction of Bi-6s lone pair electrons, in which partial atom rearrangement makes the active sites transform into asymmetric high-spin states from symmetric low-spin states. As a result, the half-disordered Bi_xEr_2-xRu₂O₇ pyrochlores demonstrate an overpotential of ~0.18 V at 10 mA cm^-2 accompanied with excellent stability of 100 h in acidic electrolyte. Our findings not only provide a strategy for designing atom-disorder-related catalysts, but also provides a deeper understanding of the spin-related acidic oxygen evolution reaction kinetics.