Plastic waste management is a huge challenge in today's world wherein polyethylene terephthalate (PET) is one of the major contributors. Chemical upcycling of plastic waste into valuable chemicals is one of the most effective methods for plastic waste management. In this work, multivalent cobalt nanoparticles supported on silica were used as a heterogeneous catalyst for the methanolysis of PET under mild reaction conditions, wherein PET was converted into dimethyl terephthalate (DMT) as the major product in the presence of methanol. In this PET methanolysis process, the effects of various reaction parameters, such as reaction time, temperature, cobalt loading on silica and catalyst amount on the conversion of PET and the yield of DMT were investigated. The developed catalyst results in significantly high DMT yield and PET conversion under mild reaction conditions. To investigate the heterogeneous nature of the developed catalyst, recyclability studies were performed which show excellent reusability with good conversion and product yield. Thus, multivalent cobalt nanoparticles supported on silica have the advantage of good conversion efficiency, high product yield, nontoxicity, excellent recyclability, and ease of separation for the methanolysis of PET. This work is anticipated to open new avenues in the field of plastic upcycling.

中文翻译：

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二氧化硅负载的多价钴纳米粒子用于商业聚对苯二甲酸乙二醇酯废瓶的高效和可持续的甲醇分解


塑料废物管理是当今世界的一项巨大挑战，其中聚对苯二甲酸乙二醇酯 (PET) 是主要贡献者之一。将塑料废物化学升级为有价值的化学品是塑料废物管理最有效的方法之一。在这项工作中，负载在二氧化硅上的多价钴纳米颗粒被用作PET在温和反应条件下的甲醇解的非均相催化剂，其中PET在甲醇存在下转化为对苯二甲酸二甲酯（DMT）作为主要产物。在该PET甲醇解过程中，研究了反应时间、温度、二氧化硅上钴负载量和催化剂用量等各种反应参数对PET转化率和DMT产率的影响。所开发的催化剂在温和的反应条件下可显着提高 DMT 产率和 PET 转化率。为了研究所开发的催化剂的非均相性质，进行了可回收性研究，结果表明具有良好的转化率和产品收率的优异的可重复使用性。因此，二氧化硅负载的多价钴纳米粒子在PET甲醇解反应中具有转化效率好、产品收率高、无毒、可回收性好、易于分离等优点。这项工作预计将为塑料升级回收领域开辟新途径。