Novel conversion of polyethylene terephthalate into aromatic amines production through nitrogen-rich pyrolysis using Zn/CuCo₂O₄ spinel catalyst

Catalytic pyrolysis of waste plastics under nitrogen-rich conditions to produce nitrogenous compounds represents a highly promising technological approach. It can achieve high-value conversion of waste plastics and expand the synthesis process of nitrogenous products. This work uses polyethylene terephthalate (PET) as the raw material and urea as the nitrogen source to produce aromatic amines, and prepares Zn/CuCo 2 O 4 spinel catalysts to enhance the above synthesis process. The results indicate that the optimal mass ratio of PET and urea is 1:1, where the relative content of nitrogenous compounds in the liquid product reaches 86.69 %, and the selectivity of aromatic amines reaches 52.48 %. The addition of the spinel catalyst significantly improves the selectivity of aromatic amines. Compared with the CuCo 2 O 4 catalyst, ZnCo 2 O 4 exhibits superior catalytic conversion performance. The optimal addition ratio of the ZnCo 2 O 4 catalyst is 15 %, and the optimal pyrolysis temperature is 550 ℃. Under these conditions, the selectivity of aromatic amines increases by 11.11 % compared to non-catalytic pyrolysis. In addition, the obtained solid residue containing the used catalyst is considered as a potential adsorbent and can be applied in water treatment. It has significant removal ability for methylene blue dye. This work not only provides a feasible approach for the production of aromatic amines, but also provides important support for the high-value utilization of waste plastics.