TY - JOUR
T1 - Activation of Hydrogen Peroxide by a Titanium Oxide-Supported Iron Catalyst
T2 - Evidence for Surface Fe(IV) and Its Selectivity
AU - Kim, Hak Hyeon
AU - Lee, Hongshin
AU - Lee, Donghyun
AU - Ko, Young Jin
AU - Woo, Heesoo
AU - Lee, Jaesang
AU - Lee, Changha
AU - Pham, Anh Le Tuan
N1 - 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:
©
PY - 2020/12/1
Y1 - 2020/12/1
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85096588228&partnerID=8YFLogxK
U2 - 10.1021/acs.est.0c04262
DO - 10.1021/acs.est.0c04262
M3 - Article
C2 - 33179924
AN - SCOPUS:85096588228
SN - 0013-936X
VL - 54
SP - 15424
EP - 15432
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 23
ER -