Preparation of Temperature‐Sensitive Heteropolyacid Catalysts for Efficient Hydrolysis of Polyethylene Terephthalate: Reaction Kinetics Analysis

Abstract This paper focuses on the green recycling technology of Polyethylene Terephthalate (PET), which, as the most widely consumed textile fiber globally, has become a key area in textile waste recycling research. While traditional acid‐catalyzed methods have demonstrated value in PET depolymerization, the harsh acidic reaction conditions pose significant technical challenges, including catalyst deactivation and severe equipment corrosion. Based on the principles of green chemistry and engineering, this study innovatively develops a temperature‐sensitive heteropolyacid catalyst, (HOCH 2 CH 2 N(CH 3 ) 3 ) x H 3‐ x PW 12 O 40 (Ch x H 3‐ x PW 12 O 40 , x = 1, 2, 3), synthesized by ion exchange between choline chloride and phosphotungstic acid. Under optimized reaction conditions (200 °C, 7 h, solid–liquid ratio of 1:10, 0.2 g catalyst), the catalyst achieves a 99% PET conversion rate and a 96% recovery rate of terephthalic acid (rTPA), with product purity reaching 99.7%. Kinetic studies based on first‐order reaction mechanisms reveal an apparent activation energy of E a = 86.72 kJ/mol for the PET hydrolysis reaction. Notably, through temperature regulation and crystallization techniques, the used Ch x H 3‐x PW 12 O 40 catalyst can be easily recovered from the product, maintaining its catalytic activity after six consecutive cycles. This innovative system, which combines high catalytic efficiency with excellent recyclability, significantly reduces energy consumption and minimizes acidic waste emissions compared to traditional methods, providing a breakthrough solution for the development of a closed‐loop recycling system for PET.