Polyester Upcycling to Glycine via Tandem Thermochemical–Electrochemical Catalysis

Abstract Deconstruction of polyethylene terephthalate (PET) plastics into commodity chemicals such as glycine presents a promising route for waste valorization. However, directly upcycling PET into glycine via thermocatalysis typically requires harsh conditions (e.g., high H 2 pressure and elevated temperature) while suffering from limited selectivity and high carbon footprint. Herein, a cascade thermochemical–electrochemical catalysis is developed to exploit glycine from end‐of‐life PET plastics with high selectivity and yield, without the use of hydrogen gas in the entire process. PET is first degraded into oxalic acid via thermochemical oxidative depolymerization using an active and robust HY‐zeolite‐supported Au catalyst under a low O 2 pressure (0.3 MPa), and then valorize oxalic acid intermediate into glycine via a two‐step electroreduction over an earth‐abundant TiO 2 catalyst. The proposed cascade catalysis approach is resilient to impurities from realistic PET waste streams, and enables a continuous conversion of various PET goods into glycine with an overall yield of 75%. Techno‐economic analysis and life cycle assessment demonstrate that the cascade approach is a cost‐effective and low‐carbon route for PET upcycling. This hybrid thermochemical–electrochemical technology paves a way to leverage cascade catalysis for mitigating plastic pollution while producing high‐value chemicals.