Improvement of H₂O₂ Utilization by the Persistent Heterogeneous Fenton Reaction with the Fe₃O₄-Zeolite-Cyclodextrin Composite

Abstract

Most previous reports related to heterogeneous Fenton focused on improving the catalytic activity of the catalysts but ignored the consumption and utilization efficiency of hydrogen peroxide (H 2 O 2 ), which has caused a large invalid waste of H 2 O 2 . This paper reports a Fe 3 O 4 -zeolite-cyclodextrin (F-Z-C) heterogeneous Fenton catalyst that can prolong the reaction duration time and improve the H 2 O 2 utilization. The pollutants can be adsorbed to the catalyst surface by the zeolite and the Fe 3 O 4cyclodextrin nanostructure, which will increase the local concentration of pollutants. Meanwhile, the H 2 O 2 dispersed in water can be temporarily captured and stored by β-cyclodextrin, decreasing the invalid consumption of free H 2 O 2 . A series of experiments indicate that the F-Z-C catalyst can store H 2 O 2 and release out slowly in a certain condition. Benefiting from the "storage-release" effect of F-Z-C on H 2 O 2 , the utilization efficiency of H 2 O 2 can be greatly improved. As a result, the contradiction between the large needed amount and the low concentration of H 2 O 2 can be solved in practical wastewater treatments.

Insight into the Enhanced Photo-Fenton Degradation Performance of Fe3O4@β-Ketoenamine-Linked Covalent Organic Framework

“…VASP was further employed to investigate the interactions between the framework fragments with H 2 O 2 . As expected, the H 2 O 2 molecules were adsorbed onto the fragment of COFs mostly via hydrogen bonds (O–H···O), which is consistent with a previous study . The shortest distance of 1.72 Å and the strongest binding energy of −16.7 eV were obtained between H 2 O 2 and TpTta COF (Figure d–f and Table ), demonstrating that H 2 O 2 more easily accepts the electron and yields • OH in TpTta COFs.…”

“…As expected, the H 2 O 2 molecules were adsorbed onto the fragment of COFs mostly via hydrogen bonds (O−H•••O), which is consistent with a previous study. 33 The shortest distance of 1.72 Å and the strongest binding energy of −16.7 eV were obtained between H 2 O 2 and TpTta COF (Figure 4d−f and Table 2), demonstrating that H 2 O 2 more easily accepts the electron and yields • OH in TpTta COFs. This is in accordance with the degradation performance result obtained for pristine COFs (Figure 3c).…”

Heterogeneous Fenton catalysts: A review of recent advances

“…In a recent study, Wang et al . prepaid a Fe 3 O 4 -zeolite-cyclodextrin catalyst (F-Z-C), which acted as a nano-reactor capable of controlling the local reactant concentration ( Wang et al, 2020 ). Cyclodextrins are known for forming inclusion complexes with the guest molecules through van der Waals forces, chemical bonds etc ( Saenger, 1980 ).…”

Coactivation of Hydrogen Peroxide Using Pyrogenic Carbon and Magnetite for Sustainable Oxidation of Organic Pollutants

“…At the optimal catalyst dosages, only 1.0 mM H 2 O 2 was required for the efficient removal of 20 mg• L −1 of ciprofloxacin (Figure 3c). This H 2 O 2 dosage is obviously lower than that used in ordinary Fenton processes (30−6000 mM) 51,52 and biochar-activated processes (10 mM) 53 and should be resulted from the high utilization of H 2 O 2 in the coactivation process. Nevertheless, the efficiency of C700/Fe 3 O 4 /H 2 O 2 on pollutant removal depends heavily on pH, just like that observed in the heterogeneous Fenton process.…”