Upcycling of polyethylene to gasoline through a self-supplied hydrogen strategy in a layered self-pillared zeolite

Conversion of plastic wastes to valuable carbon resources without using noble-metal catalysts or external hydrogen remains an extremely challenging task. Here we demonstrate a layered self-pillared zeolite that enables the conversion of polyethylene to gasoline with an unprecedented selectivity of 99% and yields of >80% at 240 ℃ for 4 hours. The liquid product is primarily composed of branched alkanes (selectivity of 72%), affording a high research octane number of 88.0 that is comparable with commercial gasoline (86.6). In situ inelastic neutron scattering, small-angle neutron scattering, solid-2 state nuclear magnetic resonance, X-ray absorption spectroscopy and isotope-labelling technique reveal that polyethylene was activated by the open Framework Tri-coordinated Al sites (oFTAl), followed by β-scission and isomerisation on Brönsted acids sites, accompanied by hydride transfer over oFTAl via a self-supplied hydrogen pathway to yield branched alkanes selectively. This study has unlocked the potential of layered zeolite materials in challenging upcycling of plastic wastes.