文献类型：期刊文献

英文题名：Highly Selective Upgrading of Polyethylene into Light Aromatics via a Low-Temperature Melting-Catalysis Strategy

作者：Zhang, Zhe[1];Chen, Huan[1];Li, Guixiang[1];Hu, Wenheng[1];Niu, Bo[1];Long, Donghui[1,2];Zhang, Yayun[1,2]

机构：[1]East China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Key Lab Specially Funct Polymer Mat & Related Tech, Minist Educ, Shanghai 200237, Peoples R China

年份：2024

卷号：14

期号：4

起止页码：2552

外文期刊名：ACS CATALYSIS

收录：;EI(收录号：20240715556250);WOS:【SCI-EXPANDED(收录号:WOS:001160860600001)】；

基金：This work was financially supported by the National Natural Science Foundation of China (No. 22008073), the Shanghai Sailing Program (No. 20YF1410600), the Fundamental Research Funds for the Central Universities, and the Shanghai Talent Development Fund (2021021).

语种：英文

外文关键词：polyethylene upgrading; light aromatics; lowtemperature; melting catalysis; ZSM-5

摘要：The selective upgrading of polyethylene waste into light aromatics is hampered by relatively high C-C bond cleavage temperatures and low product selectivity. Herein, we report a low-temperature melting-catalysis strategy that directly upgrades low-density polyethylene (LDPE) into light aromatics over commercial ZSM-5 zeolite under mild conditions, eliminating the need for precious metals, solvent, or external H-2. Experimental results combined with DFT calculations and molecular dynamics simulations revealed that the molten LDPE microenvironment facilitates intimate LDPE-catalyst contact, promoting primary C-C cleavage while suppressing olefin intermediates diffusion out of pores. This feature increases the residence time for subsequent direct olefin cyclization within the confined micropores. Moreover, online mass spectra confirmed that the in situ generated hydrogen from cyclization and dehydroaromatization reactions plays a vital role in C-C bond scission. By optimizing the reaction conditions, a light aromatic yield of 50.6 wt % with an impressive selectivity of 90.9% toward benzene, toluene, and xylenes was achieved at 280 degrees C for 1 h. This strategy is not limited to the model polyethylene but also demonstrates remarkable efficiency in the depolymerization of various widely used polyethylene-rich plastics, enabling an economically viable and environmentally benign chemical recycling path for plastic wastes.