Rational Design of Oxygen Electrocatalysts Guided by Reaction Intermediates

• • 4f-modified Ru–O polarity functions as a descriptor for acidic OER, with the cited Nat. Commun. 2025, 16: 6921 study demonstrating that f-electron modulation alters Ru–O covalency and reduces the OER overpotential; this matters industrially because Ru is roughly 20–30% the cost of Ir, and stabilizing Ru in acid at >10 mA/cm² for >100 h directly addresses the cost-stability trade-off in PEM electrolyzers. • • Spin-balanced Janus Ir–Co magnetic atoms (Nano-Micro Lett., 2026, 18: 227) achieve efficient acidic water oxidation by tuning spin occupancy at the active site; spin-state control can lower the rate-determining *OOH formation barrier by 0.1–0.2 eV, translating to a 30–60 mV reduction in overpotential at 10 mA/cm², which is operationally significant for intermittent renewable-powered electrolysis. • • Aligned d-orbital energy levels in dual-atom sites (Nat. Commun., 2025, 16: 8111) enable ORR in anion-exchange-membrane fuel cells; precise d-orbital alignment optimizes *OH and *O binding, yielding half-wave potentials approaching 0.90 V vs. RHE in alkaline media, a threshold required for AEMFC power densities above 1 W/cm² without platinum-group-metal cathodes. • • FeN6–CoN4 dual-site catalysts (ACS Catal., 2026, 16: 2800-2813) modulate ORR pathways via oxygen adsorbate evolution-to-dissociation transition, with synergistic strong–weak adsorption coupling; this shifts selectivity away from 2e⁻ peroxide production (which degrades membranes and ionomers) toward 4e⁻ reduction, directly improving durability in Zn–air batteries where peroxide attack limits cycle life to <500 cycles.