Inha University researchers identify self-decomposition mechanism for tire pollutant 6PPD-Q

Researchers at Inha University have identified a new mechanism through which 6PPD-quinone (6PPD-Q), a toxic pollutant derived from automobile tires, can facilitate its own decomposition. The study, led by Professor Chang-seok Han and doctoral student A-young Choi, was published in the journal ‘Environmental Chemistry Letters’.

6PPD-Q is a highly toxic emerging pollutant formed when the antioxidant 6PPD in tires reacts with ozone. Traditionally, advanced oxidation processes using peroxyacetic acid (PAA) to treat such pollutants require external activation, such as ultraviolet light or metal catalysts, to generate the reactive radicals necessary for decomposition.

The research team discovered that 6PPD-Q can activate PAA through an electron transfer reaction, forming semiquinone radicals. This process promotes the decomposition of PAA and the generation of active radicals even without external stimuli. In high concentrations of PAA, the pollutant effectively triggers its own breakdown regardless of UV exposure. This finding shifts the perspective of pollutants from being mere targets for removal to active agents that can drive the oxidation process required for their own elimination.