Repurposing polyethylene terephthalate plastic waste to capture carbon dioxide

Polyethylene terephthalate (PET) is a ubiquitous polymer with a lack of viable waste management solutions besides mechanical recycling, incineration, and landfilling. Herein, we demonstrate a chemical upcycling of PET waste into materials for CO2 capture via aminolysis. The aminolysis reaction products—a bis-aminoamide (BAETA) and oligomers—exhibit high CO2 capture capacity up to 3.4 moles per kilogram as a stand-alone organic solid material. BAETA shows strong chemisorption featuring high selectivity for CO2 capture from flue gas (5 to 20% CO2) and ambient air (~400 parts per million CO2) under humid conditions. Our thermally stable material (>250°C) enables CO2 capture at high temperatures (up to 170°C) for multiple cycles. Scalability of the material production was demonstrated by performing aminolysis of untreated consumer waste PET of 1 kilogram. Our approach introduces a simple and straightforward solution that can address both plastic waste and carbon dioxide, offering a potential pathway toward net negative emissions.