Sustainable Closed‐Loop Recycling of Polyester Waste Using Reconstructed Defective‐Metal–Organic Frameworks

Abstract

Abstract Chemical recycling of polyester waste presents a promising strategy for achieving a sustainable circular economy. However, the development of efficient, low‐cost recycling methods that minimize energy consumption and carbon emissions remains challenging. Here, we report an approach for depolymerization polyester waste to bis (hydroxyethyl)terephthalate (BHET) using a reconstructed metal–organic framework ( r ‐Zn–MOF74–NT) catalyst under mild conditions. The r ‐Zn–MOF74–NT exhibited a space‐time yield of 1035.8 g BHET g cat −1  h −1 at 190 °C. Importantly, this is an order of magnitude higher than that reported for similar MOF‐based catalysts. In situ spectroscopy combined with theoretical calculations revealed that the depolymerization pathway involves the activation of oxygen and ethylene glycol adsorbed on r ‐Zn–MOF74–NT, forming nucleophilic intermediates. These intermediates then facilitate the cleavage of the polyester C─O bond through nucleophilic attack, thereby gradually generating the BHET product. Sustainability evaluation results validated the circular economy feasibility of the recycling approach, with a minimum sales price (MSP) of 498 $/ton, much lower than the MSP of the traditional petroleum‐based production route (1000 $/ton). The approach also achieved a 61% reduction in energy use and a 52% decrease in greenhouse gas emissions. This work provides a sustainable solution for managing polyester waste accumulation.