StrikingInfluence about HZSM-5 Content andNickel Catalyst on Catalytic Carbonization of Polypropylene and Polyethyleneinto Carbon Nanomaterials.

A one-potapproach was established to effectively convert polypropylene(PP) and linear low density polyethylene (LLDPE) into carbon nanomaterials(CNMs) including cup-stacked carbon nanotubes and carbon nanofibersunder the combined catalysis of HZSM-5/NiO or HZSM-5/Ni2O3at 700 °C. The effects of HZSM-5 content, a nickelcatalyst, and the carbon precursor on the morphology, microstructure,phase structure, and thermal stability of CNMs were investigated withscanning electron microscopy, transmission electron microscopy (TEM),high-resolution TEM, X-ray diffraction, Raman spectroscopy, and thermalgravimetric analysis. The effect of HZSM-5 content on the degradationproducts of PP and LLDPE was analyzed by gas chromatography and gaschromatography–mass spectrometry. With increasing HZSM-5 content,the yields of light hydrocarbons and aromatics increased due to protonacid sites on the surface of HZSM-5 catalyzing cracking of PP or LLDPEdegradation products. This one-pot approach provides a novel potentialway to largely transform mixed waste polyolefin into high value-addedCNMs. [ABSTRACT FROM AUTHOR]