One-Pot Conversion of Polyester and Carbonate into Formate without External H₂

Abstract

The coconversion of two kinds of waste materials, plastics and CO 2 , into a single value-added product is an innovative and challenging endeavor that simultaneously achieves the upcycling of plastic waste and reduces CO 2 emissions. Herein, we report a one-pot, two-step catalytic process for transforming polyesters, such as poly(glycolic acid), carbonate, and water, into sodium formate with a high yield of 79%, using a commercial Pd/C catalyst. This process involves the aqueous-phase reforming of polyester with water at 250−270 °C and the hydrogenation of NaHCO 3 at 150 °C, utilizing H 2 generated during the reforming process. Notably, no external H 2 or other reactive reagents are required. This strategy can be applied for the coconversion of poly(ethylene terephthalate) (PET), poly(butylene-adipate-co-terephthalate) (PBAT), and commercial biodegradable plastic bags with Na 2 CO 3 obtained from CO 2 capture via a NaOH solution, opening up a new path for "turning trash into treasure".

Recent advances in CO2 reduction with renewable reductants under hydrothermal conditions: towards efficient and net carbon benefit CO2 conversion

“…This technique effectively resolves the contradictions in reaction temperature and pressure between plastic reforming and NaHCO 3 hydrogenation, achieving a 79% yield of HCOONa. 103 Additionally, CO 2 facilitates the conversion of polyethylene (PE) into aromatics, achieving synergistic resource utilization, as shown in Fig. 13c .…”

Co-upcycling of Plastic Waste and Biowaste via Tandem Transesterification Reactions

“…In this context, chemical upcycling of PET waste into depolymerized aromatic monomers or higher-value chemicals is a more attractive recycling strategy. Various methods have been explored for the valorization of PET waste, , including hydrogenolysis, − solvolysis, , pyrolysis, photocatalytic , and electrochemical upcycling, and hybrid processes. − However, most of these methods require additional inputs of valuable chemicals and energy resources, such as H 2 , alcohols, intensive heat, and electricity.…”