MgO/NaY as modified mesoporous catalyst for methanolysis of polyethylene terephthalate wastes

The treatment and reuse of polyester wastes have received widespread attention. In this work, MgO/NaY catalysts with different MgO contents were prepared by the incipient-wetness impregnation method and used in the methanolysis of PET for the first time, proposing a convenient and feasible method to solve the plastic recycling crisis. To characterize the surface and structural properties of the prepared MgO/NaY catalysts by EDXRF, BET, XRD, SEM, FT-IR and TEM. The acid-base properties of the catalysts were also characterized by CO2-TPD and NH3-TPD. The relationship between acid-base and catalytic activity showed that the conversion of PET and the yield of DMT increased with the increase of alkalinity of the catalyst. The results showed that the PET conversion and the DMT yield could reach 99% and 91%, respectively, under the reaction conditions of 200 °C, 30 min, catalyst dosage of 4 wt%, and the mass ratio of methanol to PET of 6 with 21%MgO/NaY as the catalyst. The recyclability of the catalyst was investigated, and the 21%MgO/NaY catalyst still had excellent catalytic activity for the methanolysis of PET after 6 cycles.