Salt-templated transformation of waste plastics into single-atom catalysts for environmental and energy applications.

Upcycling plastic waste into single-atom catalysts (SACs) not only offers a sustainable solution for plastic waste management but also yields valuable functional materials for catalytic applications. Here, we report a simple and scalable method to transform various types of plastics, including polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polyvinyl chloride, and their mixtures, into a diversity of porous SACs with different coordination chemistry and their excellent applications in a variety of catalytic reactions. Lamellar transition metal chloride salts (Ni, Fe, Co, Mn, and Cu) are employed as a template and catalyst for confined carbonization of plastics into layered SACs. An appropriate plastic-to-salt ratio is the key factor for preventing metal agglomeration during SAC synthesis. The SACs demonstrate exceptional catalytic activity in oxidative degradation of a range of persistent organic pollutants for water treatment and excel in electrocatalytic systems such as oxygen/nitrogen reduction reactions and lithium-sulfur batteries. This technique provides a versatile, scalable, and efficient strategy for upcycling solid wastes into high-performance materials for environmental and energy catalysis.