Synthesis of Clean Hydrogen Gas from Waste Plastic at Zero Net Cost

Abstract Hydrogen gas (H 2 ) is the primary storable fuel for pollution‐free energy production, with over 90 million tonnes used globally per year. More than 95% of H 2 is synthesized through metal‐catalyzed steam methane reforming that produces 11 tonnes of carbon dioxide (CO 2 ) per tonne H 2 . “Green H 2 ” from water electrolysis using renewable energy evolves no CO 2 , but costs 2–3× more, making it presently economically unviable. Here catalyst‐free conversion of waste plastic into clean H 2 along with high purity graphene is reported. The scalable procedure evolves no CO 2 when deconstructing polyolefins and produces H 2 in purities up to 94% at high mass yields. The sale of graphene byproduct at just 5% of its current value yields H 2 production at a negative cost. Life‐cycle assessment demonstrates a 39–84% reduction in emissions compared to other H 2 production methods, suggesting the flash H 2 process to be an economically viable, clean H 2 production route.