A Minimalist Design for a Dual-Catalyst System for High-Efficiency Conversion of Waste Plastics into Liquid Fuel Products

Chemical conversion of waste plastics into valuable products holds immense significance for pollution control and resource conservation. Dual-catalyst systems exhibit improved overall efficiency compared with conventional bifunctional catalysts in hydrocracking processes, but they continue to grapple with the issues of high noble metal loadings and the necessity for meticulously controlled synthesis steps. Herein, we propose a minimalist design for a dual-catalyst system that combines exceptional catalytic efficiency, minimal noble metal consumption, and a streamlined synthesis process. Specifically, Ce-modified HY (CeHY) and CeO2-supported Rh (Rh-CeO2) were directly blended as catalysts for low-density polyethylene (LDPE) hydrocracking. This blend achieves an ultrahigh liquid fuel formation rate of 3132 g/gnoble metal/h, surpassing the previously reported dual-catalyst systems. Mechanistic analysis reveals that the enhanced performance mainly originates from unique interactions between CeO2 and Rh, which allows the coexistence of Rh single atoms (Rh1) and Rh nanoparticles (Rhn). These served as active sites for adsorbing olefin intermediates and activating H2, respectively, thereby promoting the hydrogenation step. More significantly, considering the structural similarity between CeHY and commercial fluid catalytic cracking (FCC) catalysts, we further performed the catalysis using SOY-8 (a commercial FCC catalyst) and Rh-CeO2, achieving equally excellent catalytic performance. The following 40-fold scale-up experiment firmly confirms the practical application prospect of our physically mixed catalytic system.