Interfacial microdroplets reshape the oxidation pathways of polycyclic aromatic hydrocarbons

-type skeletal rearrangement, yielding fluorene-type rearrangement products. More importantly, microdroplet-based oxidation has limited ability to fully mineralize PAHs but instead promotes the accumulation of characteristic intermediates (such as hydroxylation and rearrangement products). This study reveals a previously unrecognized interfacial oxidation pathway of phenanthrene, providing new insights into the interfacial reaction chemistry of aromatic molecules.