Electrochemical Production of Glycolate Fuelled By Polyethylene Terephthalate Plastics with Improved Techno‐Economics

Abstract

Electrochemical valorization of polyethylene terephthalate (PET) waste streams into commodity chemicals offers a potentially sustainable route for creating a circular plastic economy. However, PET wastes upcycling into valuable C2 product remains a huge challenge by the lack of an electrocatalyst that can steer the oxidation economically and selectively. Here, it is reported a catalyst comprising Pt nanoparticles hybridized with γ‐NiOOH nanosheets supported on Ni foam (Pt/γ‐NiOOH/NF) that favors electrochemical transformation of real‐word PET hydrolysate into glycolate with high Faradaic efficiency (> 90%) and selectivity (> 90%) across wide reactant (ethylene glycol, EG) concentration ranges under a marginal applied voltage of 0.55 V, which can be paired with cathodic hydrogen production. Computational studies combined with experimental characterizations elucidate that the Pt/γ‐NiOOH interface with substantial charge accumulation gives rise to an optimized adsorption energy of EG and a decreased energy barrier of potential determining step. A techno‐economic analysis demonstrates that, with the nearly same amount of resource investment, the electroreforming strategy towards glycolate production can raise revenue by up to 2.2 times relative to conventional chemical process. This work may thus serve as a framework for PET wastes valorization process with net‐zero carbon footprint and high economic viability.

Upgrading polyethylene terephthalate plastic into commodity chemicals paired with hydrogen evolution over a partially oxidized CuIn5S8 nanosheet photocatalyst

“…Therefore, commercial PET granules were first depolymerized into a PET hydrolysate via alkaline hydrolysis (1.5 M KOH), which was subsequently utilized as a feedstock for the photocatalytic reaction. 48 As illustrated in Fig. 4a, the average H 2 evolution rate over O-CuIn 5 S 8 is 2.57 ± 0.02 mmol g −1 h −1 , which is about 7 times higher than that of pristine CuIn 5 S 8 (0.36 ± 0.02 mmol g −1 h −1 ), indicating the enhanced photocatalytic activity after oxygen incorporation into the photocatalyst.…”

Electroreforming injects a new life into solid waste

“…In our recent work, to highlight the advantages of a Pt/NiOOH heterostructure for the selective transformation of ethylene glycol to glycolic acid with respect to bare Pt and NiOOH, the adsorption ability and the reaction pathway are calculated. 211 As shown in Fig. 11a, the Pt/NiOOH interface enabled the lowest adsorption energy for ethylene glycol among all the models, indicating the favorable reactant adsorption process over Pt/NiOOH.…”

“…210 However, glycolic acid generation with high selectivity remains challenging due to the uncontrollable and severe C-C bond cleavage followed by the formation of formic acid during ethylene glycol oxidation. Currently, the selective conversion of ethylene glycol to glycolic acid is only enabled by noble metals, such as Pt, 211 Pd, 212 and Au. 213 A recent work from Shi et al 206 reported PdAg/NF electrocatalysts to evoke the transformation from ethylene glycol to glycolic acid with high selectivity and faradaic efficiency (Fig.…”

Symmetry or asymmetry: which one is the platform of nitrogen vacancies for alkaline hydrogen evolution

“…[10][11][12][13] To date, Pt-based materials are still recognized as benchmark catalysts for the alkaline HER owing to the favorable kinetics for water dissociation over Pt sites. However, their large-scale deployment is significantly obstructed by the low earth abundance and high cost, [14][15][16][17] necessitating the exploration of alkaline HER catalysts with enhanced activity and economic applicability.…”