High-efficiency Ce-modified ZSM-5 nanosheets for waste plastic upgrading

Zeolite-based catalyst hydrocracking of plastics is a potential strategy for mitigating the environmental impacts of plastic wastes and recycling valuable resources, but difficult mass transfer, low concentration of acid sites, and high cost are still barriers to their practical applications. In this paper, we report an excellent hydrocracking catalyst of ZSM-5 nanosheets (Ce/b-ZSM-5) modified by Ce species with high conversion up to 96.3%, C₃−C₅ selectivity up to 80.9%, and good stability during the hydrogenation of low-density polyethylene. Through comprehensive studies, b-ZSM-5 shows higher molecular diffusion efficiency and acid site concentrations compared with normal ZSM-5 (n-ZSM-5) and hollow ZSM-5 (h-ZSM-5). The introduction of Ce species into b-ZSM-5 further increases the density of Brønsted (B) and Lewis (L) acid sites as active sites, which enhances the adsorption of substrates and facilitates the formation of intermediates and desorption of products. As a result, the hydrocracking activity of Ce/b-ZSM-5 is significantly improved.