Enhanced Fenton-like catalysis by iron-based metal organic frameworks for degradation of organic pollutants

• Published in: Journal of catalysis Vol. 356; pp. 125 - 132
• Main Authors: Gao, Cong, Chen, Shuo, Quan, Xie, Yu, Hongtao, Zhang, Yaobin
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.12.2017
• Subjects: active sites; catalysts; catalytic activity; coordination polymers; ferric oxide; Heterogeneous Fenton-like catalysts; hydrogen peroxide; Hydroxyl radicals; iron; Iron-based MOFs; Mechanism; MIL-88B-Fe; phenol; pollutants; pollution control; sludge; Iron-based MOFs; MIL-88B-Fe; Hydroxyl radicals; Heterogeneous Fenton-like catalysts; Mechanism
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2017.09.015

[Display omitted] •MIL-88B-Fe exhibited high catalytic activity and stability in Fenton-like processes.•Coordinatively unsaturated irons were the active sites of MIL-88B-Fe.•Contact of H2O2 with the active sites was necessary for the Fenton-like reaction.•Enhanced Fe(III)/Fe(II) redox cycle of MIL-88B-Fe contributed to its high catalytic activity. The Fenton reaction is an efficient technology for degrading refractory organic pollutants in water. Heterogeneous Fenton-like catalysts have been demonstrated to be promising alternatives to homogeneous catalysts because of their reusability and lack of sludge production. These catalysts, however, generally show low activity for generating OH due to their limited exposed active sites and difficulty in the reduction of Fe(III) to Fe(II). Here, enhanced catalytic performance was achieved by using an iron-based metal organic framework (MIL-88B-Fe) as a heterogeneous Fenton-like catalyst over a wide pH range (4–6). The catalytic activity of MIL-88B-Fe was about 1–3 orders of magnitude higher than that of three other conventional catalysts (Fe2O3, α-FeOOH, and Fe3O4) and two other iron-based MOFs (MIL-53-Fe and MIL-101-Fe). The superior activity of MIL-88B-Fe could originate from the abundance of active sites, the flexible structure, and facilitated reduction of Fe(III) to Fe(II). Hydroxyl radicals generated from reaction between MIL-88B-Fe and H2O2 were the main reactive oxidative species for phenol degradation.