Nanoscale FeO Electrocatalysts for Oxygen Reduction Reaction.

This study presents a straightforward hydrothermal synthesis approach to fabricate uniform and highly dispersed nanoscale FeO electrocatalysts for the oxygen reduction reaction (ORR). FeSO·7HO is used as the precursor, and sodium dodecyl sulfate (SDS) is incorporated as a dispersing agent to optimize particle size and dispersion. The SDS concentration plays a crucial role in controlling the particle size and distribution, with higher SDS concentrations resulting in smaller, well-dispersed particles (30-40 nm), compared to the agglomerated particles formed without SDS. The FeO catalyst demonstrates significant enhancement in ORR performance, with a half-wave potential of 0.091 V vs. Hg/HgO and a limiting diffusion current density of -5.50 mA cm, surpassing the performance of agglomerated FeO and approaching that of state-of-the-art 20% Pt/C catalysts. Additionally, the FeO catalyst exhibits superior stability and resistance to methanol and CO poisoning, presenting a promising alternative to platinum-based catalysts for ORR applications. This work introduces an efficient approach for the synthesis of high-performance and evenly distributed FeO electrocatalysts, offering a new pathway for the development of metal oxide-based ORR catalysts with enhanced activity and durability.