Influence of iso-valent Al3+ doping on the electrocatalytic activity of La0.5Sr0.5Co0.8Fe0.2−xAlxO3−δ (x = 0–0.2) perovskite oxides.

Autor: Mandal, Rupesh, Sanket, Kumar, Das, Subhadip, Behera, Shantanu K., Pratihar, Swadesh K.
Předmět:
Zdroj: Journal of Solid State Electrochemistry; Jun2024, Vol. 28 Issue 6, p1809-1827, 19p
Abstrakt: Perovskite oxides have been recognized as superior oxygen evolution reaction (OER) catalysts under alkaline conditions, allowing for more flexibility in cation distribution. Numerous OER-active Co-rich perovskites have demonstrated excellent activity and stability with partially doping metals at the B-site. At the current stage, there is still ambiguity regarding the role of Fe, its partial replacement at the B-site, and how these factors will affect OER activity and stability of the material. The solution-combustion technique is used to prepare perovskite-type La0.5Sr0.5Co0.8Fe0.2−xAlxO3−δ (x = 0–0.20) oxides. This study elucidates the influence of partially Al-doping on perovskite OER performance in 1 M KOH. The physicochemical properties of the synthesized materials are investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Brunauer–Emmett–Teller (BET) surface area analysis, and X-ray photoelectron spectroscopy (XPS). XPS results revealed that fractional replacement of Fe with Al-cation altered the oxidation states of B-site cations and enhanced the surface oxygen vacancy. Among the studied catalysts, LSCFA0.10 showed the highest intrinsic activity and stability in 1 M KOH. The optimized catalyst exhibited a low overpotential of 490 mV at a current density of 10 mA cm−2 and a Tafel slope of 50.6 mV dec−1 for OER, analogous to noble materials like RuO2 and IrO2. This finding indicates that LSCFA0.10 perovskite shows high activity due to large surface area, surface oxygen vacancy, and faster charge transfer rate, providing efficient OER performance and can also be utilized as an economical electrocatalyst for OER performance. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index