Abstract:
Energy storage and conversion driven by electro- or
photocatalyst is a highly exciting field of research, and generations of
effective and durable oxide catalysts have received much attention in this
field. Here, we report A-site lanthanum-doped oxygen-rich quinary oxide
CaLaScRuO6+δ synthesized by adopting the solid-state reaction method
and characterized by various techniques such as powder X-ray diffraction,
neutron diffraction, energy-dispersive X-ray spectroscopy, inductively
coupled plasma-atomic emission spectrometry, Raman spectroscopy, and
temperature-programmed reduction in the presence of a hydrogen
atmosphere (H2-TPR). X-ray absorption study confirms the existence of
mixed valent Ru ions in the structure, which enhances the oxygen stoichiometry for the partial balance of an extra cationic charge.
Neutron powder diffraction and reduction of the material in a hydrogen atmosphere (H2-TPR) can confirm the oxygen
overstoichiometry of the catalyst. The present material works as an efficient and robust oxygen bifunctional electrocatalyst for ORR/
OER (oxygen evolution reaction/oxygen reduction reaction) followed by four-electron transfer pathway in a strong (1 M KOH)
alkaline medium. The catalytic nature of the designed structural and chemical flexible perovskite is a novel example of an
electrocatalyst for the oxygen bifunctional activity.
