Abstract Thermo-chemical conversion of plastics provides an economic flexible and environmentally friendly method to recycle waste plastics, and generates valuable materials, such as carbon nanotubes (CNTs) and syngas. The development of catalysts is a key challenge for improving the quantity and quality of CNTs. In this study, spherical catalysts loaded with Ni were studied to control CNTs growth using waste plastic as the feedstock. Three parameters were studied, including catalytic temperature, Ni content and plastics/catalysts ratio. A fixed two-stage reactor was used for thermal pyrolysis of plastic waste and the materials were characterized with various methods including scanning electronic microscopy (SEM), temperature programme oxidation (TPO) and X-ray diffraction (XRD). The results showed that different contents of Ni loaded on sphere results in the formation of metal particles with various sizes, thus leading to CNTs production with different quantity and quality. In addition, an optimal catalytic temperature at 800 °C is suggested for CNTs formation with the Ni/sphere catalyst, as the catalyst might not be activated at 600 °C and 700 °C.

中文翻译：

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用废聚乙烯制备碳纳米管的球形氧化铝负载催化剂的研究

摘要 塑料的热化学转化为回收废塑料提供了一种经济灵活且环境友好的方法，并产生有价值的材料，如碳纳米管 (CNTs) 和合成气。催化剂的开发是提高碳纳米管数量和质量的关键挑战。在这项研究中，研究了负载镍的球形催化剂以使用废塑料作为原料来控制碳纳米管的生长。研究了三个参数，包括催化温度、Ni 含量和塑料/催化剂比。采用固定式两级反应器对废塑料进行热解，并采用扫描电子显微镜（SEM）、程序升温氧化（TPO）和X射线衍射（XRD）等多种方法对材料进行表征。结果表明，不同含量的Ni负载在球体上会导致形成不同尺寸的金属颗粒，从而导致不同数量和质量的碳纳米管生产。此外，建议使用 Ni/球形催化剂形成 CNT 的最佳催化温度为 800°C，因为催化剂可能不会在 600°C 和 700°C 下活化。