Inhibit effect of Pr，Ce，La or Yb doping on microwave-assisted pyrolysis of waste plastics for by-production oil over Co-Fe catalysts

Plastic waste causes serious pollution to the environment. Being not satisfied with simply disposing of them into environment, people want to efficiently convert it into high-value products, such as H 2 and carbon nanotubes . A trimetallic catalyst is provided herein, which adds Pr, Ce, La or Yb to a Co-Fe bimetallic catalyst to inhibit the formation of oil by-product in a plastic pyrolysis reaction. In this work,various plastics，including plastics with different functional groups and real plastic waste were used for pyrolysis with elemental hydrogen efficiencies above 95% in the gas product. For pyrolysis of EVA, the gaseous hydrogen efficiency reached 96.07%, and for pyrolysis of LLDPE , the gaseous hydrogen efficiency reached 95.56%, over Pr 1 Co 1 Fe 8 O x catalyst. The role of Pr in catalytic reactions is discussed in general and the formation of carbon nanotubes of various types of structures is simulated. Catalyst cycling experiments demonstrate that the catalyst still maintains a gas hydrogen efficiency of more than 70% after being used four times. In conclusion, the Pr 1 Co 1 Fe 8 O x catalyst proved to be the best choice for microwave-assisted catalytic pyrolysis of plastics to H 2 , and this work provides a new perspect for the study of plastic pyrolysis.