Polyethylene Upgrading to Liquid Fuels Boosted by Atomic Ce Promoters

• Published in: Angewandte Chemie Vol. 136; no. 8
• Main Authors: Wu, Xueting, Wang, Xiao, Zhang, Lingling, Wang, Xiaomei, Song, Shuyan, Zhang, Hongjie
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 19.02.2024
• Subjects: Catalysis; Catalysts; Fuels; Hydrocracking; Intermediates; LDPE Upgrading; Liquid fuels; Low density polyethylenes; Plastic debris; Polyethylene; Promoter; Promoters; Rare Earth; Zeolite
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.202317594

Hydrocracking catalysis is a key route to plastic waste upgrading, but the acid site‐driven C−C cleavage step is relatively sluggish in conventional bifunctional catalysts, dramatically effecting the overall efficiency. We demonstrate here a facile and efficient way to boost the reactivity of acid sites by introducing Ce promoters into Pt/HY catalysts, thus achieving a better metal‐acid balance. Remarkably, 100 % of low‐density polyethylene (LDPE) can be converted with 80.9 % selectivity of liquid fuels over the obtained Pt/5Ce‐HY catalysts at 300 °C in 2 h. For comparison, Pt/HY only gives 38.8 % of LDPE conversion with 21.3 % selectivity of liquid fuels. Through multiple experimental studies on the structure‐performance relationship, the Ce species occupied in the supercage are identified as the actual active sites, which possess remarkably‐improved adsorption capability towards short‐chain intermediates. We demonstrate a significantly‐promoted low‐density polyethylene upgrading process with a high selectivity of liquid fuels by introducing Ce promoters into Pt/HY catalysts. The Ce species in the supercage are identified as the actual active sites, which possess remarkably‐improved adsorption capability towards short‐chain intermediates, thus contributing to the accelerated rate of second‐round C−C cleavage.