Photothermal conversion of polyoxymethylene into syngas over supported alloyed nanocrystals

Plastic pollution has become an increasingly severe environmental threat, accompanied by significant resource wastage. Polyoxymethylene (POM), a widely used engineering plastic, presents recycling challenges as conventional methods often require high temperatures or strong acids and are accompanied by the release of hazardous formaldehyde gas. In this study, we demonstrate a green and mild photothermal catalytic strategy for the upcycling of waste POM using a supported PtGa alloy catalyst. The incorporation of gallium (Ga), which exhibits strong near-infrared absorption, enhances the catalyst’s light-harvesting capability and photothermal efficiency. Under full-spectrum irradiation without external heating, the catalyst rapidly reaches elevated temperature, efficiently promoting POM depolymerization and syngas generation. Notably, light irradiation modulates the reaction pathway, achieving a high syngas yield to 20.32 mmol gcat−1 h−1 with 89.0% selectivity. This work establishes a promising strategy for the sustainable valorization of engineering plastics into high-value chemical feedstocks.