CuCl-embedded polyethylene terephthalate waste-derived porous carbon for efficient CO adsorption

The upcycling of waste plastics into functional porous carbon offers a sustainable strategy for mitigating environmental pollution. In this study, waste polyethylene terephthalate (PET) was converted into porous carbon and functionalized with copper(I) chloride (CuCl) for selective carbon monoxide (CO) adsorption. The optimized adsorbent, prepared at a 1:1 mass ratio of PET-derived carbon to CuCl, exhibited an outstanding CO uptake of 3.66 mmol/g at 25 ℃ and 101.3 kPa. It also showed excellent CO selectivity under steel-industry-relevant flue gas conditions and maintained over 98% of its working capacity during ten adsorption–desorption cycles. For practical separation, the prepared adsorbent was pelletized using methylcellulose as a binder. The adsorbent pelletized with a powder-to-binder mass ratio of 1:0.1 retained approximately 90% of the CO uptake of the original powder form, achieving 3.23 mmol/g at 25 ℃ and 101.3 kPa. It also exhibited high CO selectivity, 13.0 and 94.1 over CO₂ and N₂, respectively, under the simulated coke oven gas conditions. This study presents a scalable and sustainable approach to upcycling plastic waste into high-performance, CO-selective adsorbents, bridging material innovation and industrial feasibility.