CO2-facilitated upcycling of polyolefin plastics to aromatics at low temperature

作     者：Yi Ding Shuchi Zhang Cheng Liu Yu Shao Xiulian Pan Xinhe Bao Yi Ding;Shuchi Zhang;Cheng Liu;Yu Shao;Xiulian Pan;Xinhe Bao

作者机构：State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences University of Chinese Academy of Sciences Department of Chemical PhysicsUniversity of Science and Technology of China 

出 版 物：《National Science Review》 (国家科学评论(英文版))

年 卷 期：2024年第11卷第5期

页      面：236-243页

核心收录：

学科分类：083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 081702[工学-化学工艺] 081705[工学-工业催化] 08[工学] 0817[工学-化学工程与技术] 

基　　金：supported by the National Natural Science Foundation of China (22321002) 

主　　题：polyolefins carbon dioxide aromatics upcycling bifunctional catalysis 

摘      要：Plastics are one of the most produced synthetic materials and largest commodities, used in numerous sectors of human life. To upcycle waste plastics into value-added chemicals is a global challenge. Despite significant progress in pyrolysis and hydrocracking, which mainly leads to the formation of pyrolysis oil,catalytic upcycling to value-added aromatics, including benzene, toluene and xylene（BTX）, in one step, is still limited by high reaction temperatures（500°C） and a low yield. We report herein CO2-facilitated upcycling of polyolefins and their plastic products to aromatics below 300°C, enabled by a bifunctional Pt/Mn Ox-ZSM-5 catalyst. ZSM-5 catalyzes cracking of polyolefins and aromatization, generating hydrogen at the same time, while Pt/Mn Ox catalyzes the reaction of hydrogen with CO2, consequently driving the reaction towards aromatization. Isotope experiments reveal that 0.2 kg CO2is consumed per 1.0 kg polyethylene and 90% of the consumed CO2is incorporated into the aromatic products. Furthermore, this new process yields 0.63 kg aromatics（BTX accounting for 60%）, comparing favorably with the conventional pyrolysis or hydrocracking processes, which produce only 0.33 kg aromatics. In this way, both plastic waste and the greenhouse gas CO2are turned into carbon resources, providing a new strategy for combined waste plastics upcycling and carbon dioxide utilization.