A highly porous MgAl2O4 spinel-supported Mn3O4 as a reusable catalyst for glycolysis of postconsumer PET waste

A porous MgAl2O4 spinel-supported Mn3O4 catalyst, which is an efficient and robust catalyst for poly-ethylene terephthalate (PET) glycolysis, was synthesized from MgAl-layered double hydroxide (LDH) as a template via thermal and chemical treatment, followed by Mn oxide loading. A mesoporous structure in the MgAl2O4 spinel provided a high surface area (278 m2/g) and defects in which Mn3O4 was highly dispersed and strongly stabilized by the substitution of Al3+ and incorporation of Mn cation into the defects. The strong interaction of Mn oxide and the porous MgAl2O4 spinel support led to a dramatic increase of moderate acidic and basic properties, and to high resistance for Mn leaching during glycolysis. Using the Mn3O4/p-spMgAl800 catalyst, a yield of bis(2-hydroxyethyl) terephthalate > 95 % was achieved within 3 h at 190 degrees C. Despite eleven recycling times with regeneration, the catalytic activity remained without significant deactivation and was completely recovered after thermal regeneration at 500 degrees C.(c) 2022 The Authors. Published by Elsevier B.V. on behalf of The Korean Society of Industrial and Engi-neering Chemistry. This is an open access article under the CC BY license (http://creativecommons.org/ licenses/by/4.0/).

Automated summary

A porous MgAl2O4 spinel-supported Mn3O4 catalyst shows high efficiency and stability in the glycolysis of PET, with a high surface area and resistance to Mn leaching.