(521p) Mechanistic Understanding of the Efficient Hydrocracking of Waste Polyethylene on Two-Dimensional Pt/WO3.

Chemical upcycling of plastic wastes by hydrocracking provides a powerful and promising strategy to recycle the waste as valuable resources. However, the decomposition of polyethylene requires harsh conditions. Herein, we introduce platinum uniformly immobilized on 2D tungsten oxide nanosheet catalyst with cooperating active sites for high-density polyethylene (HDPE) hydrocracking. A complete conversion of HDPE is achieved at mild conditions, producing narrow-distributed products in the gasoline and diesel base-fuel range at an extraordinarily high formation rate of 1456 g_product∙g_{active species}^-1∙h^-1. Moreover, quasi-operando FTIR-online GC system was employed to investigate the hydrocrack process of HDPE. Reactivity studies combined with quasi-operando investigation reveal that: (I) the abundant vacancies and strong oxygen affinity of WO₃ species triggered the absorption of HDPE chains in form of C=O intermediates and activation of C-C cleavage; (II) the superior activity derived from the hydrogen spillover on the well dispersed Pt species on the 2D-WO₃ which facilitate dehydrogenation of polymer chains over the surface of Pt/WO₃ catalyst.