Synergetic electrocatalytic degradation of isophorone by active oxygen species generated in the gas diffusion...

Significant efforts have been made to achieve efficient H₂O₂ generation via oxygen reduction reaction (ORR). Here, the acetylene black (AB)-based gas diffusion electrodes (GDEs) modified by PTFE were fabricated and applied in a closed autoclave for H₂O₂ generation for the first time. The surface morphology, BET, XPS, cyclic voltammetry curves and linear scanning voltammetry curves of GDEs were all characterized. Additionally, the H₂O₂ generation experiments of GDEs and the relationship between H₂O₂ yield and BET surface area (S_BET), double layer capacitance (C_dl) were all investigated. It could be found that the S_BET and C_dl of GDEs kept a good linear relationship with H₂O₂ content, and 2#GDE (AB:PTFE = 1:3) possessed the optimal H₂O₂ generation capacity. Also, the effect of oxygen pressure and current density on H₂O₂ production was evaluated detailedly, indicating higher oxygen pressure was beneficial to the H₂O₂ generation and the preferable current density was 20 mA cm^-2 due to the side reactions. And all the H₂O₂ electro-generation experiments exhibited a higher oxygen utilization efficiency (0.77%-2.93%). Finally, the efficient and synergetic electro-catalytic degradation of isophorone was achieved by self-made PbO₂ anode and GDE.