Study on Mechanism and Kinetics of Waste Polymethyl Methacrylate Cracking Oxidation Over CeO ₂ /REY Catalyst

ABSTRACT Catalytic cracking oxidation is an environment‐friendly technology for converting organic solid waste into CO 2 and H 2 O. Using thermo‐gravimetric (TG) analysis, derivative of thermal gravity (DTG), differential scanning calorimetry (DSC), TG mass spectrometry (TG‐MS), and in situ Fourier transform infrared spectroscopy (FTIR), this study investigated the catalytic cracking oxidation reaction of polymethyl methacrylate (PMMA) over model catalysts to clarify its reaction mechanism and kinetic behavior. Through analysis of weight loss, exothermic profiles, product distribution, and functional group changes, we found that PMMA underwent dominant cracking over rare earth Y (REY) zeolite, oxidation over CeO 2 and coupled cracking‐oxidation over CeO 2 /REY. Mechanistically, PMMA was first cracked into low‐molecular‐weight organics (e.g., esters and ketones) at acid sites on CeO 2 /REY then oxidized to CO 2 and H 2 O at redox sites. Kinetic analysis using the distributed activation energy model (DAEM) showed that catalyst addition increased the activation energy compared to the pure PMMA pyrolysis, suggesting that enhanced cracking–oxidation coupling contributed to this increase. This work provides a theoretical basis for optimizing the catalytic cracking oxidation process and enhances the fundamental understanding of catalytic cracking oxidation mechanisms.