Synthesis of Brownmillerite-type Ca2Fe0.5Co1.5O5 as a Durable Electrocatalyst for Oxygen Evolution Reaction in Neutral Aqueous Solution

OKADA Hiroyuki, TSUJI Etsushi, SUGANUMA Satoshi, KATADA Naonobu

doi:10.5796/electrochemistry.25-00133

Green hydrogen production and carbon dioxide electroreduction in neutral aqueous solutions, are key reactions for zero-carbon energy systems. In both cases, the oxygen evolution reaction (OER) is a counter reaction that requires a high overpotential. Therefore, active and durable OER catalysts at neutral pH are demanded. We previously reported that brownmillerite-type Ca₂Fe_0.75Co_1.25O₅ calcined at 1073 K exhibits higher OER activity and durability than that of perovskite-type iron cobalt oxides and Ca₂Fe₂₋_xCo_xO₅ (x ≤ 1) at neutral pH. Here, we synthesized Ca₂Fe_0.5Co_1.5O₅ at temperatures between 1073 and 1373 K and compared its OER activity and durability at neutral pH with those of Ca₂FeCoO₅ and Ca₂Fe_0.75Co_1.25O₅. X-ray diffraction and chemical composition analysis revealed that pure brownmillerite phase of Ca₂Fe_0.5Co_1.5O₅ was only achieved at 1273 K, while samples calcined at lower and higher temperatures contained Ca₃Co₂O₆ and CaO impurities, respectively. The Ca₂Fe_0.5Co_1.5O₅ exhibited the highest activity and durability for over 100 h, significantly outperforming Ca₂Fe_0.75Co_1.25O₅ without significant changes in morphology or bulk composition.

Synthesis of Brownmillerite-type Ca<sub>2</sub>Fe<sub>0.5</sub>Co<sub>1.5</sub>O<sub>5</sub> as a Durable Electrocatalyst for Oxygen Evolution Reaction in Neutral Aqueous Solution

書誌事項

この論文をさがす

説明

収録刊行物

参考文献 (41)*注記

関連プロジェクト

キーワード

詳細情報詳細情報について

書き出し

問題の指摘