ORR/OER Path

Nature Catalysis: How to change the NiFe OER reaction pathway by neglecting dissolved Fe?

NiFe-based hydroxides are one of the most classic catalytic systems in basic OER (Organic Emission Reduction). Previous understanding of them mainly focused on Fe sites on the solid surface: Fe incorporation into NiOOH forms highly active centers, promoting OER. This Nature Catalysis paper presents a more dynamic interfacial picture: during OER, the NiFe catalyst undergoes Fe dissolution and redeposition, with some dissolved Fe species transforming into FeO₄²⁻, which then participates as a molecular co-catalyst in the key O–O bonding step. Theoretical calculations further illustrate that surface *O can synergistically form the *OOFeO₃ intermediate with FeO₄²⁻ in solution, shifting OER from the traditional solid-surface AEM pathway to a solid-molecular synergistic pathway.