Realizing High and Stable Electrocatalytic Oxygen Evolution for Iron‐Based Perovskites by Co‐Doping‐Induced Structural and Electronic Modulation

Abstract

Oxygen evolution reaction (OER) is a vital electrochemical process for various energy conversion and fuel production technologies. Co/Ni-rich perovskite oxides are extensively studied as promising alternatives to precious-metal catalysts; however, low-cost and earth-abundant iron (Fe)-rich perovskites are rarely investigated to date due to their poor activity and durability. This study reports an Fe-rich Sr 0.95 Ce 0.05 Fe 0.9 Ni 0.1 O 3−δ (SCFN) perovskite oxide with minor Ce/Ni co-doping in A/B sites as a high-performance OER electrocatalyst. Impressively, SCFN shows more than an order of magnitude enhancement in mass-specific activity compared to the SrFeO 3−δ (SF) parent oxide, and delivers an attractive small overpotential of 340 mV at 10 mA cm −2 , outperforming many Co/Ni-rich perovskite oxides ever reported. Additionally, SCFN displays robust operational durability with negligible activity loss under alkaline OER conditions. The increased activity and stability of SCFN can be ascribed to co-doping-induced synergistic promotion between structural and electronic modulation, where Ce doping facilitates the formation of a 3D corner-sharing cubic structure and Ni doping gives rise to strong electronic interactions between active sites, which is key to achieving a highly active long-life catalyst. Importantly, this strategy is universal and can be extended to other Fe-based parent perovskite oxides with high structural diversity.

Activity-Stability Relationships in Oxide Electrocatalysts for Water Electrolysis

“…Such advanced material designs give broad opportunities to improve the stability of perovskite oxide catalysts such as combining current collectors, active and/or stable catalyst materials in multi-layer structures ( Akbashev et al, 2018 ; Baniecki et al, 2019 ), tuning surface stoichiometry ( Baeumer et al, 2021a ), applying modulation doping ( Heymann et al, 2022 ), chemical substitution and atomic ordering phase-control ( Gunkel et al, 2017 ; Zhu et al, 2021 ; She et al, 2022 ). In addition to material optimization, electrolyte engineering can be applied to avoid surface passivation ( Chung et al, 2020 ).…”

Iridium‐Doped 10H‐Phase Perovskite BaCo0.8Fe0.15Ir0.05O3–δ as an Efficient Oxygen Evolution Reaction Catalyst

“…[ 18 ] Shao and co‐workers synthesized hexagonal perovskite material Sr 0.95 Ce 0.05 Fe 0.9 Ni 0.1 O 3– δ by co‐doping, which owns high activity and good stability in alkaline conditions. [ 19 ] The co‐doping induced synergistic promotion between structure and electronic modulation successfully improves the activity and stability. The strategy is universal and can be applied to other systems.…”

High Selectivity Electrocatalysts for Oxygen Evolution Reaction and Anti-Chlorine Corrosion Strategies in Seawater Splitting

“…Both reactions need highly efficient electrocatalysts to overcome energy consumption overpotentials. After a wide variety of research efforts and tremendous advancements, researchers have successfully developed many excellent electrocatalysts for OERs and HERs, which can significantly promote the application of water splitting [13][14][15][16][17][18][19][20]. However, electrocatalysts that are both stable and highly active are still insufficient to the task, so direct electrolysis of seawater to generate H 2 remains challenging.…”