Continuous Glycolic Acid Electrosynthesis Enabled by Ethylene Glycol-Mediated PET Valorization Using Nanoporous PdCu...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Poly-(ethylene terephthalate) (PET) plastic waste presents a significant environmental challenge.
• Electrochemical conversion of PET into glycolic acid (GA) is a promising upcycling strategy.
• Existing methods suffer from low selectivity and reaction rates due to complex reaction pathways and mass transport limitations.

Purpose of the Study:

• To develop a robust and efficient nanocatalyst for the electrochemical valorization of PET-derived ethylene glycol into GA.
• To investigate the catalytic mechanism and structural properties of the novel catalyst.
• To demonstrate the long-term stability and performance of the catalyst in a flow cell system for continuous GA production.

Main Methods:

• Fabrication of a nanoporous PdCu nanocatalyst using electrochemical dealloying of a PdCu3 intermetallic precursor.
• In-situ electrochemical ICP-MS and surface-enhanced IR spectroscopy for catalyst characterization and reaction pathway analysis.
• Electrochemical testing in a membrane-free flow cell electrolyzer to evaluate GA electrosynthesis performance.

Main Results:

• A Pd-skin/intermetallic PdCu3 core nanoporous structure (∼ 2.4 nm) was successfully synthesized.
• The catalyst demonstrated high structural stability and favored a C2 pathway for GA formation.
• Achieved a high mass activity of 9.95 A mgPd−1 and >92% Faradaic efficiency for GA.
• Continuous GA electrosynthesis at 200 mA cm−2 for over 110 h with 86.6%–95.4% efficiency and 0.51 gGA/gPET yield.

Conclusions:

• The developed PdCu nanocatalyst significantly enhances the efficiency and selectivity of PET electrochemical valorization.
• The catalyst's unique structure and composition enable effective plastic upcycling into valuable chemicals.
• This work provides a viable pathway for sustainable plastic waste management and chemical production.