LAUSR

Efforts to selectively convert polypropylene (ca. 30% of all plastic waste) have not been particularly successful. Typical distributions span from gas to solid products, highlighting a challenging cleavage control. We design carbon-supported platinum nanoparticles for complete hydrocracking into liquid hydrocarbons (C5-C45). The metal and carrier phases operate synergistically. The cleavage activity lies on platinum and its rate rises with decreasing particle size. The carbon carrier controls selectivity via hydrocarbon binding strength, which depends on the chain length and on the surface oxygen concentration. An optimal binding provided by carbons with high oxygen content promotes both adsorption of long chains and desorption of short products. This strategy achieved an unprecedented 80% selectivity toward motor oil (C21-C45). Carbons exhibiting too strong binding (low oxygen content) hinder product desorption, while non-binding materials (e.g., silica or alumina) do not promote plastic-Pt contact, leading in both cases to low performance. This work pioneers design guidelines in a key process towards a sustainable plastic economy.