Interfacial ozone chemistry enables aromatic oxidation in microdroplets

Developing safer and more sustainable oxidation strategies for aromatic hydrocarbons remains a key challenge in green chemistry due to the reliance on hazardous oxidants and metal catalysts. Here, we demonstrate that ozone (O₃) can be generated in situ at aqueous microdroplet air–water interfaces and directly utilized for the selective oxidation of naphthalene (NA) under mild, catalyst-free conditions. In an ultrasonic microdroplet system, NA is converted into dimethyl phthalate (DMP) with an isolable yield of 11.6%. Ozone formation and reaction occur concurrently within the confined droplet environment, eliminating the need for external ozone generation. Experimental and theoretical studies support an interfacial O₃-mediated pathway initiated by transient discharge events. These results demonstrate the potential of microdroplet interfaces as a platform for inherently safer ozone-mediated oxidation.