폐 PET 해중합 반응을 위한 재사용 및 재생이 가능한 Mn 치환 MgAI₂O₄ 스피넬 촉매

Mn-substituted MgAI₂O₄ spinel as a reusable and regenerable heterogeneous catalyst for glycolysis of post-consumer PET

Catalytic glycolysis with ethylene glycol (EG) is a promising method for recycling PET with lower CO₂ emissions and the production of monomer-level PET. Various catalysts have been explored for this process, with metal oxides offering advantages in terms of separation, preparation cost. and reusability through regeneration. However, using a high EG concentration to achieve high BHET monomer selectivity in PET glycolysis can lead to issues such as residue deposition on the catalyst and metal oxide dissolution in the solvent at elevated temperatures. To address these challenges, it is crucial to develop a catalyst that is not only highly stable during the reaction but also recyclable and regenerable. Spinel, known for their exceptional thermal and chemical stability, offer a solution. Additionally, the acidic and basic properties of spinel can be adjusted by partially substituting them with various metal cations. Taking into account the characteristics of spinel, Mn-substituted MgAI₂O₄ (MnxMg₁-xAl₂O₄, x= 0-0. 3) were successfully synthesized by co-precipitation and applied to PET glycolysis as catalyst. The conversion of PET over the MnxMg₁-xAl₂O₄ catalyst is monotortically increased from 37.1% (x=O) to 100% (x= 0. 25) and the selectivity to BHET was achieved to 95%. The recyclability and regenerability of Mn-substituted MgAI₂O₄ were also conducted.