New Insights into the Mechanism of the Catalytic Decomposition of Hydrogen Peroxide by Activated Carbon: Implications for Degradation of Diethyl Phthalate

This study investigated the catalytic decomposition of H₂O₂ by activated carbon (AC) and its implications for degradation of diethyl phthalate (DEP). It was found that AC exhibited excellent catalytic ability for decomposition H₂O₂ and degradation of DEP. HNO₃ modification altered the surface characteristics of AC together with the concentrations and types of AC free radicals (FRs), which further promoted generation of ^•OH. Positive correlations were found between FR concentration and generation of ^•OH (<i>R</i>² = 0.856) and between the proportion of surface-bound hydroxyl groups (C–OH) and the decomposition rate of H₂O₂ (<i>R</i>² = 0.776), indicating that FRs in AC were the main contributor to ^•OH generation, whereas C–OH groups were predominantly responsible for decomposition of H₂O₂. Electron capturing studies demonstrated that the decomposition reaction likely involves the transfer of FR electrons to H₂O₂ to induce formation of ^•OH