Immobilization of [Bmim] OAc on ZnO Nanoparticles: Synthesis, Catalytic Performance, and Kinetic Evaluation for PET Glycolysis

ABSTRACT The chemical recycling of polyethylene terephthalate (PET) via glycolysis requires catalysts that combine high activity with facile separation. In this work, 1‐butyl‐3‐methylimidazolium acetate ([Bmim]OAc) was immobilized onto ZnO nanoparticles via an ultrasound‐assisted method to produce a heterogeneous catalyst with cooperative acid–base functionality. Comprehensive characterization (XRD, FTIR, XPS, SEM, and TGA) confirmed uniform immobilization of the ionic liquid, preserved the wurtzite ZnO structure, and generated an ordered interfacial environment. At a catalyst loading of 0.4 wt%, 196°C, and PET:EG = 1:6, complete depolymerization of PET was obtained after 2 h, yielding 82.8% BHET. The reaction kinetics conformed to an apparent first‐order model, with a calculated activation energy of 151.4 kJ·mol −1 , reflecting the combined contributions of interfacial and chemical processes in this heterogeneous system. DFT calculations indicate an OH bond length of 0.978 Å in ethylene glycol and a hydrogen‐bond interaction (1.978 Å) with the acetate anion, consistent with a cooperative Lewis acid–base interaction.