ReaxFF MD simulation of microwave catalytic pyrolysis of polypropylene over Fe catalyst for hydrogen

Microwave-assisted catalytic pyrolysis of waste plastics is promising for hydrogen generation. To study the mechanism of microwave in Fe catalyzed pyrolysis of plastics. Molecular dynamics (MD) simulation was carried out using the ReaxFF method to compare the bonded and non-bonded interatomic interactions at the same temperature under conventional heating and microwave heating at different powers. The results show that the microwave improves the adsorption capacity of Fe clusters, reduces the dissociation energy of C-H bonds, and promotes the cleavage of C-C bonds due to H radicals at low temperature. Therefore, microwave enhances the generation of H-2, reduces the required reaction temperature, and suppresses the generation of small gaseous hydrocarbon molecules and tar. These results prove the reliability of ReaxFF MD and provide a theoretical basis for valorising waste plastics aided by microwave.