Oxygen-Evolution Reaction Promoted by Iron and Brass Under Alkaline Conditions

Abstract

Herein, the oxygen-evolution reaction (OER) performance of brass foil modified with K2FeO4 under alkaline conditions (pH approximate to 13) is investigated. The effect of Fe from the K2FeO4 source on the OER activity on brass foil was systematically explored. The experiments demonstrate a significant enhancement in the performance of the OER with the incorporation of K2FeO4, reducing the overpotential required for the initiation of the OER by 120 mV on brass foil. Moreover, the Tafel slope decreased from >130 mV/decade to 61.8 mV/decade upon K2FeO4 addition, indicating distinct catalytic sites before and after Fe incorporation. In situ visible spectroelectrochemistry revealed the formation of CuHxOy compounds on the electrode surface during the OER in the presence of K2FeO4 and brass, elucidating the mechanistic insights of catalytic activity enhancement. The utilization of brass foil highlights the potential advantages of alloy catalysts over pure metals, offering enhanced durability, efficiency, and catalytic activity under oxidative conditions. Furthermore, the removal of Zn from brass alloys increases the surface area available for interaction with Fe, further improving catalytic performance. These findings underscore the importance of comprehensive studies involving a range of metal alloys to harness synergistic effects for electrocatalysis, potentially leading to cost reduction, extended catalyst life, and optimized performance in diverse operational environments.