In Situ Hydrogen Utilization in Plastic Waste Recycling and Upcycling

Abstract The management of waste plastics poses a significant challenge due to their inherent chemical stability, large-scale production, and short service life. As plastics are primarily composed of carbon and hydrogen, there is growing interest in the high-value conversion of plastic waste for the targeted production of hydrogen. However, the thermodynamic constraints of the processes, along with the associated challenges in hydrogen storage and transportation, limit the practical application of hydrogen production technologies derived from plastic waste. Consequently, in situ utilization of hydrogen generated from plastic waste has emerged as a promising strategy. This perspective elucidates the fundamental principles of in situ hydrogen utilization and establishes a theoretical framework for evaluating existing studies and guiding future research. Based on this framework, we systematically assess the latest advancements, critically addressing the challenges encountered and proposing directions for future research. The objective of this paper is to provide a comprehensive roadmap for the efficient utilization of hydrogen energy derived from plastic waste, thereby facilitating the establishment of a hydrogen circular economy.