Activating PFAS to Unlock Efficient Defluorination

Per- and polyfluoroalkyl substances (PFAS) are highly resistant to conventional degradation methods due to the exceptional stability of their C-F bonds. As a result, current degradation technologies often rely on high energy inputs and excessive use of additives while largely overlooking strategies that focus on lowering the reaction energy barrier by directly activating PFAS molecules or ions. This Perspective presents a new angle to PFAS degradation by emphasizing the predegradation activation of PFAS molecules. We systematically examine a range of molecular activation mechanisms facilitated by catalyst surface complexation, solvents, salts, and air-water microinterfaces. These methods destabilize PFAS molecules by elongating C-F bonds or altering surface electronic structures and charge distributions, thereby overcoming the activation barriers (ΔG^‡) for subsequent defluorination reactions. Additionally, we outline future directions that incorporate multimodal activation and emerging data technologies, such as intelligent reactor design and machine-learning-guided optimization, with the goal of bridging fundamental molecular insights and practical engineering applications. Molecular activation thus offers a transformative pathway to overcome kinetic and energetic challenges, paving the way for energy-efficient, cost-effective, and broadly applicable solutions to eliminate these persistent "forever chemicals" from the environment.