Tuning Exsolution Behavior and Boosting OER Performance via High-Valence W Doping in LaCo0.8Fe0.15W0.05O3-δ Perovskites

The exsolution of nanoparticles from perovskite oxides has attracted considerable attention for oxygen evolution reaction (OER) applications owing to their exceptional stability and catalytic activity. Understanding and controlling the surface exsolution behavior of nanoparticles is critical for tuning the catalytic activity and stability of perovskite oxide. Herein, we investigate the effect of high-valence tungsten (W) doping on the exsolution behavior and OER performance of LaCo 0.8 Fe 0.15 W 0.05 O 3-δ perovskite. Compared with the pristine perovskite, W doping elevates the exsolution temperature from 600 to 650 °C, indicating a significant influence on both thermodynamics and kinetics processes. The reduced electrocatalyst exhibits remarkable OER performance, achieving an overpotential of 234 mV at 10 mA cm −2 in 1.0 M KOH, along with low Tafel slope (67 mV dec −1 ), small charge transfer resistance (20 Ω) and long-term stability, underscoring its superior charge transfer kinetics and electrical conductivity. This work provides valuable insights into the role of high-valence dopants in modulating exsolution behavior, offering guidance for the rational design of highly efficient for energy conversion applications. Graphical High-valence W doping in LaCo 0.8 Fe 0.15 W 0.05 O 3-δ increases the exsolution temperature from 600 to 650 °C and significantly enhances oxygen evolution reaction performance, achieving an overpotential of 234 mV at 10 mA·cm −2 , a Tafel slope of 67 mV·dec −1 , and a charge transfer resistance of 20 Ω, providing critical insights for designing new electrocatalysts.