Cen Ziyu, Han Xue, Lin Longfei, Yang Sihai, Han Wanying, Wen Weilong, Yuan Wenli, Dong Minghua, Ma Zhiye, Li Fang, Ke Yubin, Dong Juncai, Zhang Jin, Liu Shuhu, Li Jialiang, Li Qian, Wu Ningning, Xiang Junfeng, Wu Hao, Cai Lile, Hou Yanbo, Cheng Yongqiang, Daemen Luke L, Ramirez-Cuesta Anibal J, Ferrer Pilar, Grinter David C, Held Georg, Liu Yueming, Han Buxing
Beijing National Laboratory for Molecular Sciences, CAS Laboratory of Colloid and Interface and Thermodynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Center for Carbon Neutral Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, China.
School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing, China.
Nat Chem. 2024 Jun;16(6):871-880. doi: 10.1038/s41557-024-01506-z. Epub 2024 Apr 9.
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。在此，我们报道了一种层状自支撑沸石，它能够在240°C下4小时内将聚乙烯转化为汽油，选择性高达99%，产率>80%。液体产物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铝位点促进了聚乙烯的活化，随后在布朗斯台德酸位点上发生β-断裂和异构化，同时通过自供氢途径在开放骨架三配位铝位点上发生氢化物转移，从而产生对支链烷烃的选择性。这项研究展示了层状沸石材料在实现塑料废物升级循环利用方面的潜力。
