Zeng Wei, Zhao Yanfei, Zhang Fengtao, Li Rongxiang, Tang Minhao, Chang Xiaoqian, Wang Ying, Wu Fengtian, Han Buxing, Liu Zhimin
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, 100190, Beijing, China.
University of Chinese Academy of Sciences, 100049, Beijing, China.
Nat Commun. 2024 Jan 2;15(1):160. doi: 10.1038/s41467-023-44604-1.
Chemical recycling of plastic wastes is of great significance for sustainable development, which also represents a largely untapped opportunity for the synthesis of value-added chemicals. Herein, we report a novel and general strategy to degrade polyesters via directly breaking the C-O bond by nucleophilic substitution of halide anion of ionic liquids under mild conditions. Combined with hydrogenation over Pd/C, 1-butyl-2,3-dimethylimidazolium bromide can realize the deconstruction of various polyesters including aromatic and aliphatic ones, copolyesters and polyester mixtures into corresponding carboxylic acids and alkanes; meanwhile, tetrabutylphosphonium bromide can also achieve direct decomposition of the polyesters with β-H into carboxylic acids and alkenes under hydrogen- and metal-free conditions. It is found that the hydrogen-bonding interaction between ionic liquid and ester group in polyester enhances the nucleophilicity of halide anion and activates the C-O bond. The findings demonstrate how polyester wastes can be a viable feedstock for the production of carboxylic acids and hydrocarbons.
塑料废弃物的化学循环利用对可持续发展具有重要意义，这在很大程度上也代表了合成增值化学品的一个尚未充分利用的机会。在此，我们报道了一种新颖且通用的策略，即在温和条件下通过离子液体的卤化物阴离子的亲核取代直接断裂C-O键来降解聚酯。结合在Pd/C上的氢化反应，1-丁基-2,3-二甲基咪唑溴化物可以实现将包括芳香族和脂肪族聚酯、共聚酯以及聚酯混合物在内的各种聚酯解构为相应的羧酸和烷烃；同时，四丁基溴化鏻在无氢和无金属条件下也能实现含β-H聚酯直接分解为羧酸和烯烃。研究发现，离子液体与聚酯中酯基之间的氢键相互作用增强了卤化物阴离子的亲核性并活化了C-O键。这些发现表明聚酯废料如何能够成为生产羧酸和碳氢化合物的可行原料。
