Industrially viable and selective catalytic system: simple and sustainable pathway for efficient degradation of waste polyester textiles

Abstract

Waste textile recycling is hampered by their complexity and high crystallinity, leading to substantial environmental pollution and resource wastage. Although enzymatic polyester recycling has promising substrate specificity, natural enzymes lack stability and activity on high-crystallinity substrates, and thus are limited in industrial viability. Herein, in light of the degradation mechanism of polyethylene terephthalate (PET) hydrolyase, we established a simple ethylene glycol (EG) selective catalytic system, possessing a nucleophilic attack mechanism on ester bonds similar to that of the catalytic serine residue in the natural enzyme. The EG catalytic system achieved efficient PET degradation, with a PET conversion rate of 99.63% and a terephthalic acid (TPA) yield of 95.46% under mild conditions (90 °C for 1 h). Meanwhile, the insolubility of the degradation products in EG catalytic system facilitates their separation, allowing the reaction system to be recycled at least five times. Additionally, first-principles molecular dynamics simulations revealed that the EG catalytic system generates active species EG⁻, which follows the same reaction mechanism as natural enzymes and has a lower energy barrier than alkaline hydrolysis. Notably, the process maintains effective hydrolysis capability at a 100 L scale, with selective degradation and decolorization, underscoring its industrial potential for PET degradation from colored composite textiles. Overall, this work offers a sustainable, efficient, and practical solution to the challenge of textile waste recycling.