Ni-Mg Bimetallic Catalysts for Preparation of Multi-Walled Carbon Nanotubes from Polypropylene: Influence of the Ratio of Ni/Mg

Abstract

This study designs Ni–Mg bimetallic catalysts for preparation of multi-walled carbon nanotubes (MWCNTs) from polypropylene (PP). The study further investigates the influence of Mg content on the catalytic activity of Ni catalyst. It is found that bimetallic Ni–Mg catalysts have higher reduction temperature, smaller Ni particle size and improved stability. Consequently, the addition of Mg not only enhances the yield of MWCNTs, but simultaneously improves the morphology and graphitization of MWCNTs. The activities of the bimetallic Ni–Mg catalysts are dependent on their composition. Among the different Ni–Mg bimetallic catalysts ration, Ni–Mg catalyst shows the highest activity when the ratio of Ni/Mg is 9/1. Moreover, the obtained MWCNTs presents smooth surface with highest graphitization degree. With our bimetallic Ni–Al catalyst, it is promising to achieve mass production of MWCNTs by using waste polymers as feedstock.