Pilot-Scale Photoreforming of Hydrolyzed Polylactic Acid Waste to High-Value Chemicals and H2 via Atomic Ru Integration

Abstract

Photoreforming of polylactic acid (PLA) waste into valuable chemicals offers a promising approach for environmental protection and waste valorization, yet faces challenges of low yields and harsh conditions. Herein, a Cd_0.5Zn_0.5S nanotwin catalyst decorated with Ru single atoms and clusters is reported, enabling selective photoreforming of PLA into pyruvic acid (PA) and H₂. It is demonstrated that Ru single atoms favor PA formation via hydroxyl dissociation, while the further incorporation of Ru clusters serve as active sites for H₂ production. This synergistic effect significantly enhances photocatalytic performance, achieving 96.8% PA selectivity and efficient H₂ production with a record-breaking apparent quantum efficiency of 83.7% at 400 nm. This approach is scalable for outdoor processes, utilizing direct 1 m² sunlight irradiation to deliver ≈1191 mL h⁻¹ of H₂ and 47.27 mmol h⁻¹ of PA from PLA waste, paving a viable pathway for large-scale simultaneous production of high-value chemicals and H₂.