Selective Valorization of Polyethylene Terephthalate (PET) Waste for the Electrochemical Production of Formate via Bismuth‐Based Catalysts
Shweta Shukla, Jyoti Sahu, Ramasamy KarvembuABSTRACT
Terephthalic acid (TPA) obtained from waste polyethylene terephthalate (PET) bottles by alkaline hydrolysis method, was used to synthesize Bi‐based metal‐organic framework (Bi‐TPA). The pyrolysis of Bi‐TPA yielded Bi 2 O 3 along with carbon (Bi 2 O 3 ‐C). Physicochemical characterizations revealed the formation of Bi‐TPA nanowires and Bi 2 O 3 ‐C. Bi‐TPA was used as a catalyst in the CO 2 electrochemical reduction reaction (ERR) to produce formate on the cathodic side. Ethylene glycol aqueous solution (PET hydrolysate), obtained from PET alkaline hydrolysis, was further oxidized to obtain formate using Bi 2 O 3 ‐C as a catalyst on the anodic side. Hence, this study identifies the potential of alkaline hydrolysis method of PET recycling for formate production. Faradaic efficiency of 75.2% for the formation of formate with the current density of 48 mA/cm 2 was found during CO 2 ERR at −1.8 V (vs. Ag/AgCl). Faradaic efficiency of 38.1% for the formation of formate with the current density of 18 mA/cm 2 was achieved during PET hydrolysate oxidation at 1.8 V (vs. Ag/AgCl).