Pair‐Resolved Fe–M Dual‐Atom Catalysts for Programmed PMS Activation: Mechanisms, Membrane Confinement, and Standardized Benchmarks

Why It Matters

Programmable Fe‑M DACs provide tunable oxidation routes, boosting efficiency and safety of advanced oxidation processes for complex wastewater, thereby fast‑tracking commercial adoption.

Key Takeaways

• Fe‑M dual atoms toggle PMS radical vs non‑radical pathways
• µ‑peroxo bridging controls spin coupling and selectivity
• Membrane confinement couples reaction with separation, reduces toxicity
• Standardized benchmarks improve comparability across studies
• Design rules enable targeted removal of antibiotics and PFAS

Pulse Analysis

Advanced oxidation processes (AOPs) have long relied on bulk metal oxides to activate peroxymonosulfate, often yielding uncontrolled radical cascades and secondary by‑products. The emergence of Fe‑M dual‑atom catalysts reshapes this landscape by isolating atom‑pair sites where µ‑peroxo bridges dictate spin states and electronic structures. This pair‑resolved approach enables precise control over whether PMS follows a radical‑driven pathway, generating hydroxyl radicals, or a non‑radical electron‑transfer route that preserves molecular integrity. Such programmability aligns catalyst behavior with the chemical nature of target contaminants, delivering higher selectivity and reduced mineralization of benign organics.

Integrating these DACs into membrane‑confined reactors adds a second layer of process intelligence. The membrane acts as both a physical barrier and a catalytic interface, allowing simultaneous pollutant degradation and product separation. In saline or organic‑rich effluents, flux remains stable, and the confined environment mitigates leaching, lowering ecotoxicity as confirmed by QSAR models and bioassays. The BPA case study highlighted in the review exemplifies how Fe‑Co favors a non‑radical phenoxy‑radical pathway, whereas Fe‑Ni drives hydroxylation, illustrating metal‑specific route bifurcation that can be leveraged for bespoke treatment trains.

Beyond laboratory proof‑of‑concept, the authors call for industry‑wide standards—uniform reporting of metal leaching, total organic carbon removal, and mechanistic evidence (EPR, operando XAS, DFT). By codifying these metrics, stakeholders can benchmark performance across platforms, accelerating scale‑up for emerging contaminants such as PFAS, antibiotic resistance genes, and microplastics. The distilled design rules empower engineers to match catalyst pairs with pollutant electronic profiles, paving the way for safer, more efficient AOPs in municipal and industrial water treatment.