One-Pot Conversion of Polyethylene Terephthalate into 1,4-Cyclohexanedicarboxylic Acid without External H2

Exploring the atom-economic transformation strategy for polyethylene terephthalate (PET), the most staple polyester material, can provide more approaches for the upcycling of plastic waste. Herein, we propose a one-pot process to convert PET into 1,4-cyclohexanedicarboxylic acid (CHDA) via the hydrogenation of terephthalic acid (TPA) by utilizing hydrogen stored in ethylene glycol (EG). The tandem process involving PET depolymerization, EG–H2O reforming, and TPA hydrogenation achieved high yields of CHDA (>90%) under optimized conditions. The employment of alkaline solution and combination of commercial Ru/C and Pd/C catalysts played critical roles in optimizing the reaction temperature and gaseous components so as to facilitate a one-pot reaction with enhanced hydrogen utilization. This method provides a feasible pathway for upcycling polyester waste, enabling high-selectivity product formation through efficient hydrogen utilization in a one-pot process.