Published: Jan. 1, 2024

The long-term stability of gas diffusion electrodes (GDEs) is critical for industrial H2O2 electrosynthesis from two-electron oxygen reduction reaction (2e-ORR), but has rarely been investigated. Herein, we evaluated the carbon black-polytetrafluoroethylene (CB-PTFE) based GDEs during in sodium sulfate (Na2SO4) electrolytes under industrially relevant conditions. Results show that maintained stable production with Faradaic efficiencies (FEs) ~75% ~300 h 150 mA/cm2. However, FEs then declined gradually to eventually ~15% at 840 h, after which GDE failed due water flooding. Increasing applied current density 200 mA/cm2 accelerated deterioration process and caused electrode failure 350 operation. Characterizations used varying durations indicate mainly by oxidation CB catalysts, defluorination PTFE, intercalation Na particles electrosynthesis. These three interrelating mechanisms decreased hydrophobicity, 2e-ORR activity selectivity GDEs, increased porosity GDEs. changes turn promoted decomposition progressive intrusion into internal pores electrosynthesis, thus causing gradual decreases Due properties, it challenging maintain densities. More studies are needed improve design operation resolve extend their lifetime

Language: Английский