Thermal suppression of charge disproportionation accelerates interface electron transfer of water electrolysis.

ABSTRACT: The sluggish electron transfer kinetics in electrode polarization driven oxygen evolution reaction (OER) result in big energy barriers of water electrolysis. Accelerating the electron transfer at the electrolyte/catalytic layer/catalyst bulk interfaces is an efficient way to improve electricity-to-hydrogen efficiency. Herein, the electron transfer at the Sr₃Fe₂O₇@SrFeOOH bulk/catalytic layer interface is accelerated by heating to eliminate charge disproportionation from Fe⁴⁺ to Fe³⁺ and Fe⁵⁺ in Sr₃Fe₂O₇, a physical effect to thermally stabilize high-spin Fe⁴⁺ (t_2g³e_g¹), providing available orbitals as electron transfer channels without pairing energy. As a result of thermal-induced changes in electronic states via thermal comproportionation, a sudden increase in OER performances was achieved as heating to completely suppress charge disproportionation, breaking a linear Arrhenius relationship. The strategy of regulating electronic states by thermal field opens a broad avenue to overcome the electron transfer barriers in water splitting.

SUBMITTER: Lu M 

PROVIDER: S-EPMC10769854 | biostudies-literature | 2024 Jan

REPOSITORIES: biostudies-literature