Mechanistic Understanding of Efficient Polyethylene Hydrocracking over Two‐Dimensional Platinum‐Anchored Tungsten Trioxide

• Published in: Angewandte Chemie 2023-10, Vol.135 (40)
• Main Authors: Zhou, Qimin, Wang, Deliang, Wang, Qingyue, He, Kailin, Lim, Khak Ho, Yang, Xuan, Wang, Wen‐Jun, Li, Bo‐Geng, Liu, Pingwei
• Format: Article
• Language: English
• Subjects: Alkanes; Catalysts; Chemistry; High density polyethylenes; Hydrocracking; Infrared spectroscopy; Intermediates; Liquid fuels; Low temperature; Nanostructure; Plastic debris; Platinum; Polyethylene; Tungsten; Tungsten oxides
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.202305644

Chemical upcycling of polyethylene (PE) can convert plastic waste into valuable resources. However, engineering a catalyst that allows PE decomposition at low temperatures with high activity remains a significant challenge. Herein, we anchored 0.2 wt.% platinum (Pt) on defective two‐dimensional tungsten trioxide (2D WO 3 ) nanosheets and achieved hydrocracking of high‐density polyethylene (HDPE) waste at 200–250 °C with a liquid fuel (C 5–18 ) formation rate up to 1456 g products  ⋅ g metal species −1  ⋅ h −1 . The reaction pathway over the bifunctional 2D Pt/WO 3 is elucidated by quasi‐operando transmission infrared spectroscopy, where (I) well‐dispersed Pt immobilized on 2D WO 3 nanosheets trigger the dissociation of hydrogen; (II) adsorption of PE and activation of C−C cleavage on WO 3 are through the formation of C=O/C=C intermediates; (III) intermediates are converted to alkane products by the dissociated H. Our study directly illustrates the synergistic role of bifunctional Pt/WO 3 catalyst in the hydrocracking of HDPE, paving the way for the development of high‐performance catalysts with optimized chemical and morphological properties.