二氧化二氯是一种氯的氧化物，是大气层中氟利昂参与光化学反应的中间体之一，可由两个一氧化氯自由基结合而形成。

Chlorine peroxide (also known as dichlorine dioxide or ClO dimer) is a molecular compound with formula ClOOCl. Chemically, it is a dimer of chlorine monoxide (ClO). It is important in the formation of the ozone hole. Chlorine peroxide catalytically converts ozone into oxygen when it is irradiated by ultraviolet light.