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.