Hydrocracking of polyolefins over ceria-promoted Ni/BEA catalysts

Abstract

Hydroconversion of polyolefins into primary petrochemical feedstocks, such as naphtha (C₅–C₁₂), offers a promising strategy to redirect plastic waste from landfills into the economy. Current hydrocracking strategies predominantly utilize precious metal-based catalysts, as the higher activation energy and stability issues limit the use of Earth-abundant metals (EAM). Herein, we improve the stability of Ni/BEA by incorporating a ceria promoter and demonstrate it in the hydrocracking of low-density polyethylene (LDPE). The Ce-promoted Ni/BEA catalyst achieved over 80% selectivity toward naphtha with the highest-reported naphtha productivity, outperforming current noble metal (Pt and Ru) and EAM (Ni and Co) catalysts. Catalyst evaluation and characterization underscore that ceria directly regulates metal dispersion and redox behavior and mitigates catalyst deactivation by suppressing coke formation. We correlate the promotional role of ceria to its unique hydrogen storage ability, which directly enhances metal hydrogenation ability. This work highlights exciting progress toward optimizing EAM hydrocracking catalysts for polyolefin upcycling.