Direct aqueous-phase reforming of polylactic acid

• Polylactic acid was successfully reformed in the direct aqueous phase. • Hydrogen and alkanes were obtained under low-energy conditions. • The PtRh-based catalyst exhibited the best performance, producing 10 mmol H 2 ·g −1 polylactic acid. This work investigates the potential of direct aqueousphase reforming (APR) as a sustainable strategy for plastic waste management, focusing on the direct transformation of polylactic acid (PLA), used here as a model plastic, into H 2 and alkanes. Given the growing environmental burden of landfilling, largely driven by plastic waste, the development of innovative valorization routes is urgently needed. In this study, a series of carbon supported catalysts with different active phases (Pt, PtPd, PtRh, PtRu) were synthesized and thoroughly characterized using techniques such as transmission electron microscopy, X-ray photoelectron and energy-dispersive X-ray spectroscopies, among others. Catalytic tests were conducted under mild conditions with low energy requirements (220 °C, 5.5 bar initial pressure, 4 h), revealing that PtRu and PtRh catalysts exhibited the highest H 2 yields, reaching up to 10 mmol·g −1 PLA. Analysis of the APR enabled the elucidation of the reaction pathway, providing insights into the reforming mechanism. Additionally, catalyst stability was assessed through extended reaction times and reuse experiments, confirming their reusability. These results demonstrate the technical feasibility of direct PLA conversion via APR, offering a promising route for the valorization of biodegradable plastics and establishing a base for extending the process to a broader spectrum of plastic waste.