Upcycling of non-biodegradable plastics by base metal photocatalysis

Plastics have become indispensable in our daily lives, but plastic waste has proliferated in landfills and oceans since most plastics are non-biodegradable and cannot be mechanically recycled. Exist-ing chemical recycling processes such as pyrolysis and hydrogenoly-sis typically use high temperatures, generate unnecessary green-house gas emissions, often require expensive noble metals, and show limited generality. In addition, the latest efforts in the photo-chemical upcycling of plastics near ambient temperatures are mainly restricted to polystyrene. Here, we report a base metal photo -driven upcycling of most conventional plastics such as polystyrene, polypropylene, polyethylene, polyvinyl chloride, and polyvinyl ace-tate by a tandem carbon-hydrogen bond oxidation/carbon-carbon bond cleavage reaction, with carbon recoveries up to 77% and se-lective formation of valuable, isolable products including formic, acetic, and benzoic acids. We successfully applied the optimized ambient conditions on copolymers, multilayered packaging, and actual plastic waste. Gram-scale reactions were demonstrated using a flow photoreactor with recirculation.