Rational Design of Oxygen Electrocatalysts Guided by Reaction Intermediates
Oxygen electrocatalysis underpins the viability of proton-exchange-membrane water electrolyzers and rechargeable Zn–air batteries, yet commercial deployment remains constrained by the sluggish kinetics of the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), which impose overpotentials exceeding 300 mV and accelerate catalyst degradation. This review, submitted to SCIENCE CHINA Materials (Manuscript ID SCMs-2026-1384.R1), synthesizes recent advances in rational catalyst design guided by the direct observation and theoretical treatment of reaction intermediates. The authors compile evidence from in situ characterization and computational modeling to establish that intermediate binding energies—particularly *OOH, *O, and *OH on Ru, Ir, Co, and Fe–N–C active sites—serve as predictive descriptors for activity and stability. Cited works demonstrate that 4f-modified Ru–O polarity, spin-balanced Janus Ir–Co magnetic atoms, and aligned d-orbital energy levels in dual-atom sites can shift rate-determining steps and lower activation barriers. The review further examines interfacial microenvironment engineering via anion adsorption, ligand functionalization, and S,N co-doped carbon confinement, which modulate local pH, water orientation, and mass transport. Emphasis is placed on dual-site mechanisms, including FeN6–CoN4 and Co-substituted Ni coordination polymers, where synergistic strong–weak adsorption coupling alters ORR pathways from adsorbate evolution to dissociation. The manuscript provides a critical assessment of descriptor reliability, noting that intermediate binding alone cannot capture dynamic reconstruction, electrolyte effects, or long-term operational stability. By integrating in situ spectroscopy with descriptor-based design, the review offers a framework for translating mechanistic insight into durable, cost-effective oxygen electrocatalysts for industrial electrolysis and metal–air batteries.