Engineering the orbital splitting and electronic reoccupation at alkali-metal-doped perovskites with face-shared IrO6 octahedral dimers

Abstract

The intriguing catalysts with excellent catalytic activity and durable stability in acidic oxygen evolution reaction (OER) are extremely desirable for efficient energy conversion. Herein, engineering the orbital splitting and electronic reoccupation at metal sites of alkali-metal-doped perovskites with face-shared IrO6 octahedral dimers is realized through structural distortion and symmetry breaking in an effort to boost the sluggish reaction kinetics and mitigate the degradation of the Ir-based catalysts in acidic electrolyte as well. Doping Na or K element can increase the oxidation state of Ir at IrO6 octahedral dimers, which not only displaces the Ir d-band centers for higher catalytic activity but also leads to a good stability of Ir centers with higher dissolution potentials. This work provides a new insight into enhancing the reactive activity by doping alkali metals.