Substantial quantities of discarded plastic have resulted in detrimental effects on the environment and ecosystems, calling for effective recycling of plastic wastes. Chemical methods for managing plastic wastes have been extensively studied, and selective recycling of products has grown in popularity. Pyrolysis, photocatalysis, and supercritical fluids were the main chemical methods reported for processing plastics. This article reviews reaction mechanisms and representative studies of pyrolysis, photocatalysis and supercritical fluid disposal of plastics. Three challenges are identified: first, high temperatures, above 400 °C, pose safety risks and potentially release harmful gases. Second, the photocatalytic decomposition of plastics is generally economical and environmentally friendly, however, reaction rates are uncontrollable. Third, the exceptional solubility and mass transfer properties exhibited by supercritical fluids have the potential to significantly augment the decomposition of plastics. Supercritical fluids can also serve as reactants that directly influence the thermal or kinetic mechanisms of the reaction. Whereas individual treatment methods are limited, coupled methods enable efficient plastic management and facilitate the selective acquisition of products. In particular, this review suggests that coupling photocatalysis and supercritical carbon dioxide should allow to dispose of plastics and convert carbon dioxide into valuable resources.

大量废弃塑料对环境和生态系统造成了不利影响，需要对塑料废物进行有效回收。管理塑料废物的化学方法已得到广泛研究，产品的选择性回收也越来越受欢迎。热解、光催化和超临界流体是报道的用于加工塑料的主要化学方法。本文综述了塑料热解、光催化和超临界流体处理的反应机理和代表性研究。确定了三个挑战：首先，400°C 以上的高温会带来安全风险，并可能释放有害气体。其次，塑料的光催化分解通常是经济且环保的，但反应速率不可控。第三，超临界流体表现出的优异的溶解度和传质特性有可能显着增强塑料的分解。超临界流体还可以作为直接影响反应的热或动力学机制的反应物。虽然单独的处理方法是有限的，但联合方法可以实现有效的塑料管理并促进选择性获取产品。特别是，这篇综述表明，光催化和超临界二氧化碳的结合应该可以处理塑料并将二氧化碳转化为有价值的资源。