Preparation of carbon nanotubes by catalytic pyrolysis of waste plastic: a mini review

Catalytic pyrolysis technology, particularly using polyolefin plastic waste as feedstock, has emerged as a promising approach for transforming waste plastics into carbon nanotubes, not only reducing their production cost but also achieving efficient disposal and high-value utilization of plastic waste. This work reviews the research on the preparation of carbon nanotubes from various waste plastics and summarizes the influence of metals and support on catalysts. The design of reactors and the optimization of process conditions are also critical factors influencing the yield and quality of carbon nanotubes. The growth mechanism of carbon nanotubes is systematically elucidated, encompassing radical reactions during pyrolysis, carbon dissolution-precipitation dynamics on catalytic surfaces, and subsequent structural evolution. Collectively, this review underscores the significant potential of catalytic pyrolysis in advancing sustainable plastic waste management and high-value resource recovery.