德国慕尼黑工业大学Johannes A. Lercher团队报道了串联裂解-烷基化聚烯烃低温升级回收成液态烷烃。相研究成果于2023年2月24日发表在国际顶尖学术期刊《科学》。

聚烯烃废料的选择性升级回收受到以相当高的速率裂解碳-碳（C–C）键所需的相对较高温度的阻碍。

研究人员提出了一种独特的方法，该方法使用高离子反应环境来提高聚合物反应性并降低离子过渡态的能量。将聚合物C–C键的吸热裂解与裂解产物的放热烷基化反应相结合，可使聚乙烯和聚丙烯在低于100°C的温度下完全转化为液体异烷烃（C6至C10）。这两种反应都是由氯铝酸盐离子液体中生成的路易斯酸性物质催化的。烷基化产物形成分离相，并且容易与反应物-催化剂混合物分离。

该方法可以将未加工的消费后产品转化高质量液体烷烃，且产量高。

附：英文原文

Title: Low-temperature upcycling of polyolefins into liquid alkanes via tandem cracking-alkylation

Author: Wei Zhang, Sungmin Kim, Lennart Wahl, Rachit Khare, Lillian Hale, Jianzhi Hu, Donald M. Camaioni, Oliver Y. Gutiérrez, Yue Liu, Johannes A. Lercher

Issue&Volume: 2023-02-24

Abstract: Selective upcycling of polyolefin waste has been hampered by the relatively high temperatures that are required to cleave the carbon-carbon (C–C) bonds at reasonably high rates. We present a distinctive approach that uses a highly ionic reaction environment to increase the polymer reactivity and lower the energy of ionic transition states. Combining endothermic cleavage of the polymer C–C bonds with exothermic alkylation reactions of the cracking products enables full conversion of polyethylene and polypropylene to liquid isoalkanes (C6 to C10) at temperatures below 100°C. Both reactions are catalyzed by a Lewis acidic species that is generated in a chloroaluminate ionic liquid. The alkylate product forms a separate phase and is easily separated from the reactant catalyst mixture. The process can convert unprocessed postconsumer items to high-quality liquid alkanes with high yields.

DOI: ade7485

Source: https://www.science.org/doi/10.1126/science.ade7485