Oxygen-mediated tandem polyethylene upcycling for selective aromatic synthesis.

Selective chemical upcycling of waste polyethylene (PE) into high-value aromatics is conceptually very attractive. Yet, up to now the aromatic product selectivity typically remains below 50%, mainly limited by competing hydrogenolysis. We report here a cascade process that combines the selective aerobic oxidation of hydrogen, in situ generated from PE via cleavage of C(sp3)-H, with oxygen and the endothermic aromatization of PE. Our tandem aerobic oxidation-aromatization approach boosts the catalytic activity at moderate temperatures of up to 280°C in ambient air. Concurrently, hydrogen removal shifts the chemical equilibrium favorably toward formation of aromatic products, achieving an aromatic selectivity of 78 mol%. Demonstrated on a near kilogram scale with upscaled catalysts under mild conditions, our approach offers a scalable, energy-efficient solution for the high-selectivity conversion of plastic waste into valuable chemical intermediates and solvents.