Solar reforming of plastics using acid-catalyzed depolymerization

The accumulation of plastics such as polyethylene terephthalate (PET), Nylon 66, and polyurethane (PU) presents an environmental challenge that requires scalable circular solutions. Here, we report photoreforming (PR) of acid-hydrolyzed waste plastics into H 2 and value-added products using an acid-stable photocatalyst composed of cyanamide-functionalized carbon nitride integrated with cobalt-promoted molybdenum disulfide ( Co MoS 2 –CN x ). Under AM 1.5G irradiation, Co MoS 2 –CN x yields 0.35 ± 0.02 mmol H 2 g cat −1 from PET, increasing to 1.9 ± 0.1 mmol H 2 g cat −1 under 405 nm LED (33 mW cm −2 ) irradiation. In 24 h, Nylon 66 and PU yield 1.0 ± 0.4 and 4.2 ± 0.1 mmol H 2 g cat −1 , respectively. From stability tests, the catalyst remains active over 11 days, affording up to 40% ethylene glycol conversion, 89% acetic acid selectivity, and a 9.0% quantum yield. Acid hydrolysis, enabled by recycled sulfuric acid from spent lead-acid batteries, underpins technoeconomic viability, indicating profitable solar-driven processing of ton-scale plastic waste.