Conversion of plastic wastes to valuable carbon resources without using noble metal catalysts or external hydrogen remains a challenging task. Here we report a layered self-pillared zeolite that enables the conversion of polyethylene to gasoline with a remarkable selectivity of 99% and yields of >80% in 4 h at 240 °C. The liquid product is primarily composed of branched alkanes (selectivity of 72%), affording a high research octane number of 88.0 that is comparable to commercial gasoline (86.6). In situ inelastic neutron scattering, small-angle neutron scattering, solid-state nuclear magnetic resonance, X-ray absorption spectroscopy and isotope-labelling experiments reveal that the activation of polyethylene is promoted by the open framework tri-coordinated Al sites of the zeolite, followed by β-scission and isomerization on Brönsted acids sites, accompanied by hydride transfer over open framework tri-coordinated Al sites through a self-supplied hydrogen pathway to yield selectivity to branched alkanes. This study shows the potential of layered zeolite materials in enabling the upcycling of plastic wastes.

在不使用贵金属催化剂或外部氢气的情况下将塑料废物转化为有价值的碳资源仍然是一项具有挑战性的任务。在这里，我们报道了一种层状自柱沸石，它能够将聚乙烯转化为汽油，选择性高达 99%，在 240 °C 下 4 小时内产率超过 80%。液体产品主要由支链烷烃组成（选择性为 72%），研究辛烷值高达 88.0，与商业汽油 (86.6) 相当。原位非弹性中子散射、小角中子散射、固态核磁共振、X射线吸收光谱和同位素标记实验表明，沸石的开放骨架三配位Al位点促进了聚乙烯的活化，然后在布朗斯台德酸位点上进行 β-断裂和异构化，同时通过自供氢途径在开放骨架三配位 Al 位点上进行氢化物转移，从而产生对支链烷烃的选择性。这项研究显示了层状沸石材料在塑料废物升级回收方面的潜力。