[1C10-13] Hydrogen production/energy carriers/CCU(3)

[1C13] Catalytic activity of brownmillerite Fe-Co oxide for electrochemical oxygen evolution reaction in neutral aqueous solution

○Hiroyuki Okada¹, Etsushi Tsuji¹, Satoshi Suganuma¹, Naonobu Katada¹ (1. Center for Research on Green Sustainable Chemistry, Tottori University)

Oxygen evolution reaction (OER) as the counter reaction of CO₂ reduction reaction (CO₂RR) in aqueous solutions is one of the bottleneck reactions for CO₂RR . CO₂RR generally takes place at pH 7. However, catalytic activity of known OER catalysts such as perovskite type oxides (PV) are low at pH 7 . In this study, the OER activities of brownmillerite type Ca₂Fe_2-xCo_xO5 (CFCO-x, 0≦x≦1.25) and PV synthesized by citric acid method were compared by various electrochemical measurements. The activity of CFCO-x was enhanced by increasing the Co/Fe ratio. CFCO-1 and -1.25 showed higher activity than PV. The CFCO-1.25 showed stable activity at 4.7 mA cm^-2 for 24 hours.

Keywords:oxygen evolution reaction, electrocatalysis, brownmillerite