Microwave-Driven Pyrolysis of Plastic Waste into Carbon Nanotubes and Hydrogen Using Spinel Ferrites

In this study, NiFe2O4, ZnFe2O4, and MgFe2O4 catalysts are utilized to decompose plastic into hydrogen gas, liquids, and carbon nanotubes. Ferrite nanoparticles worked as a catalyst and heat susceptors for microwaves. MgFe2O4 catalyst resulted in highly structured carbon residue with fewer impurities than other catalysts. The oil yield of 13.5, 14, and 9.5 wt. % was obtained with NiFe2O4, ZnFe2O4, and MgFe2O4, respectively. Similarly, gas evolution was about 14, 13, and 12.5 wt. %, respectively. MgFe2O4 displayed superior H2 production efficiency of 90 % compared to the other two catalysts. These findings suggest high activity of MgFe2O4 catalyst compared to NiFe2O4 and ZnFe2O4 catalysts. This catalyst also showed stronger magnetic characteristics and reactivity. Magnetic NiFe2O4, ZnFe2O4, and MgFe2O4 catalysts were used as microwave heat susceptors for deconstruction of high-density plastic into CNTs, oil, and hydrogen fuel. These materials absorbed microwaves significantly faster than single metal oxides like Al2O3 and Fe2O3 and minimized the formation of tar and char by splitting organic molecules at relatively lower temperatures. image