Activation of Hydrogen Peroxide by a Titanium Oxide-Supported Iron Catalyst: Evidence for Surface Fe(IV) and Its Selectivity

Hak Hyeon Kim, Hongshin Lee, Donghyun Lee, Young Jin Ko, Heesoo Woo, Jaesang Lee, Changha Lee, Anh Le Tuan Pham

Research output: Contribution to journalArticlepeer-review

46 Citations (Scopus)

Abstract

Iron immobilized on supports such as silica, alumina, titanium oxide, and zeolite can activate hydrogen peroxide (H2O2) into strong oxidants. However, the role of the support and the nature of the oxidants produced in this process remain elusive. This study investigated the activation of H2O2 by a TiO2-supported catalyst (FeTi-ox). Characterizing the catalyst surface in situ using X-ray absorption spectroscopy (XAS), together with X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR), revealed that the interaction between H2O2 and the TiO2 phase played a key role in the H2O2 activation. This interaction generated a stable peroxo-titania Fe(III)-Ti-OOH complex, which reacted further with H2O to produce a surface oxidant, likely Fe[IV] = O2+. The oxidant effectively degraded acetaminophen, even in the presence of chloride, bicarbonate, and organic matter. Unexpectedly, contaminant oxidation continued after the H2O2 in the solution was depleted, owing to the decomposition of Fe(III)-Ti-OOH by water. In addition, the FeTi-ox catalyst effectively degraded acetaminophen over five testing cycles. Overall, new insights gained in this study may provide a basis for designing more effective catalysts for H2O2 activation.

Original languageEnglish
Pages (from-to)15424-15432
Number of pages9
JournalEnvironmental Science and Technology
Volume54
Issue number23
DOIs
Publication statusPublished - 2020 Dec 1

Bibliographical note

Funding Information:
This work was supported by the National Research Foundation of Korea (NRF) (Grant NRF-2019R1I1A1A01059379) and the Natural Sciences and Engineering Research Council of Canada (NSERC) (Discovery Grant #2015-04850). All XANES analyses were conducted at the 1D KIST beamline of the Pohang Acceleration Laboratory (Pohang, Republic of Korea).

Publisher Copyright:
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ASJC Scopus subject areas

  • General Chemistry
  • Environmental Chemistry

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