Synergetic Effects of Molybdenum and Magnesium in Ni–Mo–Mg Catalysts on the One-Step Carbonization of Polystyrene into Carbon Nanotubes

Abstract

catalysts were systematically explored for the one-step conversion of polystyrene (PS) into carbon nanotubes (CNTs). The catalysts were characterized in the phase structure, morphology, reducibility, and carbonization performance. It was found that the Mo contributed to the small catalyst particle growth by the formation of NiMoO 4 phase. The addition of Mg had no effect on catalyst particle sizes but effectively controlled the carbon solubility and led to the growth of CNTs by the generation of NiMgO 2 . Finally, we demonstrated that the Ni−Mo−Mg catalysts showed the most efficient for the conversion of PS into CNTs owing to the individually synergetic effect of Mo and Mg elements. Besides catalysts, the degradation additives and the carbonization temperature were also discussed for their effects on the carbonization of PS. It is believed that the work provides potential for the conversion of PS waste into CNTs.

Thermochemical Valorization of Waste Plastic for Production of Synthetic Fuels, Fine Chemicals, and Carbon Nanotubes

“…Schematic illustrations for the effects of Mo and Mg on Ni active phase in synthesis of catalyst and one-step carbonization of PS to various carbon species. Adapted with permission from ref . Copyright 2017, American Chemical Society.…”

“…Despite the various one-pot approaches used in the production of CNTs, the selectivity of the carbon product is heavily dependent on the nature of the catalyst. Li et al 187 had demonstrated a direct carbonization of PS to CNTs using a Ni-Mo-Mg catalyst at 1000 °C (Figure 9). When metallic Ni is used as the catalyst, carbon spheres were obtained from the process as a result of layers of graphite forming on the metal surface, encapsulating the catalyst.…”

Upcycling Plastic Wastes into Value‐Added Products by Heterogeneous Catalysis

“…Most plastics including PE, PP, PS, and PET are mainly composed of carbon and hydrogen elements, and consequently they can serve as ideal resources for the production of value‐added carbon materials and hydrogen gas. Over the past years there has been substantial interest and research into the conversion of plastics into various carbon materials, in particular, carbon nanotubes, carbon nanofiber, graphene, and so on [79–99] . Though these carbon materials have varied morphology and structure, the synthesis procedures for them share two key steps: the degradation of plastics into small carbonaceous molecules and their subsequent carbonization.…”

Effect of Different Catalyst Supports on the Quality, Yield and Morphology of Carbon Nanotubes Produced from Waste Polypropylene Plastics

“…The authors reported that the addition of Mo resulted in the formation of small-sized catalyst particles, which resulted in the formation of carbon spheres, whereas the addition of Mg showed no effect on the catalyst particle size but efficiently improved the carbon solubility and yield. However, combining Mo and Mg resulted in the growth of CNTs of optimal yield and morphology [17].…”