Identify the impact of pyrolysis temperature on preparation of carbon nanotubes by catalytic reforming polypropylene

Catalytic reforming offers a promising method for converting waste plastics into valuable products such as carbon nanotubes (CNTs). The composition of the carbon source plays a crucial role in determining the growth of CNTs because pyrolysis temperature exerts a significant influence on volatilisation. This study investigated the impact of pyrolysis temperature on the formation of CNTs in the presence of an Fe/Al2O3 catalyst. A pyrolysis temperature of 500 degree celsius, generated a liquid product containing a high concentration of long-chain waxy hydrocarbons, while the gaseous products were dominated by C3H6 (47 vol%) and C2H6 (20 vol%). Increasing the pyrolysis temperature facilitated the formation of CH4 and aromatic hydrocarbons at the expense of the waxy components. Following catalysis, carbon deposits of > 30 wt% (comprising approximately 80 % CNTs) were obtained at 500 degree celsius, compared to 20 wt% (with CNTs comprising 60 %) at 900 degree celsius. In summary, the results suggest that small molecular hydrocarbons, including C3H6 and waxy components, promote CNT formation, whereas aromatic hydrocarbons contribute to the formation of amorphous carbon or coke.