Chen Ruizhe, Cheng Leilei, Zhang Wenbo, Gu Jing, Yuan Haoran, Chen Yong
Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences (CAS), Guangzhou, 510640, PR China; School of Energy Science and Engineering, University of Science and Technology of China, Hefei, 230026, PR China; Guangdong Provincial Key Laboratory of High-Quality Recycling of End-of-Life New Energy Devices, Guangzhou, 510640, PR China.
Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences (CAS), Guangzhou, 510640, PR China; Guangdong Provincial Key Laboratory of High-Quality Recycling of End-of-Life New Energy Devices, Guangzhou, 510640, PR China.
J Environ Manage. 2025 Sep;391:126638. doi: 10.1016/j.jenvman.2025.126638. Epub 2025 Jul 19.
The catalytic pyrolysis of polyethylene for aromatic production is a promising method for waste plastic disposal and resource recovery. This study investigated the nature of metal species and the distribution of acidic sites in low-density polyethylene (LDPE) scission-aromatization reactions using metal-loaded zeolite catalysts. Under the influence of the 1.0Zn/MOR40 catalyst, LDPE achieved a maximum aromatic selectivity of 45.71 % at 500 °C, based on the total product composition. The results indicated that catalysts with a lower Brønsted acid site to Lewis acid site ratio (BAS/LAS) and a higher concentration of [ZnOH] species favored the reaction, promoting the generation of olefin intermediates and aromatics while suppressing polycyclic aromatic hydrocarbons (PAHs) formation. However, there was an optimal range for the BAS/LAS ratio and [ZnOH] species concentration. Reaction results involving squalene and triacontane demonstrated that excessive dehydrogenation of reactants and insufficient BAS could hinder the progression of aromatization reactions, resulting in an increased proportion of PAHs. This study provides a comprehensive understanding of the balance between the synergistic and antagonistic effects of metal-acid sites on the aromatization process.
聚乙烯催化热解制备芳烃是一种很有前景的废塑料处理和资源回收方法。本研究利用负载金属的沸石催化剂，研究了低密度聚乙烯（LDPE）断链芳构化反应中金属物种的性质和酸性位点的分布。在1.0Zn/MOR40催化剂的作用下，基于总产物组成，LDPE在500℃时实现了45.71%的最大芳烃选择性。结果表明，较低的布朗斯特酸位点与路易斯酸位点比例（BAS/LAS）和较高浓度的[ZnOH]物种的催化剂有利于该反应，促进烯烃中间体和芳烃的生成，同时抑制多环芳烃（PAHs）的形成。然而，BAS/LAS比例和[ZnOH]物种浓度存在一个最佳范围。涉及角鲨烯和三十烷的反应结果表明，反应物过度脱氢和BAS不足会阻碍芳构化反应的进行，导致PAHs比例增加。本研究全面了解了金属-酸位点在芳构化过程中的协同和拮抗作用之间的平衡。
