The development of highly active oxygen evolution reaction
(OER)
electrocatalysts is one of the most important issues for advanced
water electrolysis technology with high energy efficiency. However,
according to the conventional adsorbate evolution mechanism (AEM),
the OER activity is theoretically limited with high overpotential
by the scaling relationship in binding energies of the reaction intermediates.
We propose an attractive strategy to promote OER activity by direct
O–O coupling at the interfacial active sites for Ag (x) nanoparticles decorated on La1–x
NiO3 perovskite electrocatalysts (Ag/LNO-x). The overpotential of the Ag/LNO-0.05 was 315 mV at a
current density of 10 mA cm–2
geo, which
was much lower than that of other Ag/LNO-x (x = 0, 0.3, and 0.5) and commercial iridium oxide (IrO2, 398 mV) electrocatalysts. The theoretical calculation revealed
that the improved OER electrocatalytic activity of Ag/LNO-x originated from a change in the reaction mechanism at
the interfacial active sites. At the interface, oxygen evolution via the dual-site mechanism with direct O–O coupling
becomes more favorable than that via the conventional
AEM. Finally, due to the formation of the interfacial active sites,
the synthesized Ag/LNO-0.05 electrocatalyst showed significantly enhanced
OER activity, which was 20 times higher mass activity before and 74
times after an accelerated durability test than that of the IrO2 electrocatalyst.