Catalytic materials based on metals (ions) used in the upcycling of plastics and polymers into fuels and valuable chemicals as part of sustainable development

Synthetic plastics have become an essential functional material in almost every aspect of the world around us. Their large-scale production is about 368 million tons per year and is expected to increase to about 800 million tons by 2050. Currently, less than 20 % of post-consumer plastic waste in developed countries is mechanically recycled, but recycled plastics lose their value - known as downcycling. An innovative approach is the upcycling process. The term "upcycling" refers to a form of secondary waste processing that results in higher-value products that are treated as valuable raw materials. It is necessary to use plastic waste as valuable raw materials to produce valuable hydrocarbons and fuels as part of climate neutrality and sustainable circular economy. The purpose of this review is to provide a comprehensive, critical and accessible overview of the general interest of the chemical community, as it will cover the use of a wide range of catalysts in the upcycling of polymers and plastics. Plastics (re)upcycling technologies, innovative highly active transition metal (ion) based catalytic materials, their catalytic pathways and the feasibility of designing such materials are presented. The review is in line with global and urgent environmental, scientific and social needs, not only because of greenhouse gas emissions, waste reduction, but also a key component of climate protection, which is one of the primary goals of sustainable development.