TY - JOUR
T1 - Robust iron coordination complexes with N-based neutral ligands as efficient fenton-like catalysts at neutral pH
AU - Canals, Maite
AU - Gonzalez-Olmos, Rafael
AU - Costas, Miquel
AU - Company, Anna
PY - 2013/9
Y1 - 2013/9
N2 - The homogeneous Fenton-like oxidation of organic substrates in water with hydrogen peroxide, catalyzed by six different metal coordination complexes with N-based neutral ligands, was studied at ambient conditions and initial pH 7, employing hydrogen peroxide as the terminal oxidant. At low catalyst concentration, the catalytic oxidative depletion of toluene achieved by selected catalysts was much more efficient than that obtained by the Fenton reagent at pH 3. The influence of pH, the water matrix and the catalyst/hydrogen peroxide concentration were investigated for the oxidation of toluene employing [FeCl2(bpmcn)] (1, bpmcn = N,N′-bis(2-pyridylmethyl)-N, N′-dimethyl-trans-1,2-diaminocyclohexane), the most efficient catalyst of the series. Moreover, the evolution of catalysts [FeCl2(bpmcn)] (1) and [Fe(OTf)2(Pytacn)] (3, Pytacn = 1-(2-pyridylmethyl)-4,7-dimethyl- 1,4,7-triazacyclononane, OTf = trifluoromethanesulfonate anion) during the course of the reaction was also studied by electrospray ionization mass spectrometry (ESI-MS). The oxidation products derived from toluene oxidation were also analyzed. A plausible mechanism of toluene degradation using [FeCl2(bpmcn)] (1) and [Fe(OTf)2(Pytacn)] (3) as catalysts was proposed, which involves the coexistence of a metal-based path, analogous to that operating in organic media where substrate oxidation is executed by an iron(V)-oxo-hydroxo species, in parallel to a Fenton-type process where hydroxyl radicals are formed.
AB - The homogeneous Fenton-like oxidation of organic substrates in water with hydrogen peroxide, catalyzed by six different metal coordination complexes with N-based neutral ligands, was studied at ambient conditions and initial pH 7, employing hydrogen peroxide as the terminal oxidant. At low catalyst concentration, the catalytic oxidative depletion of toluene achieved by selected catalysts was much more efficient than that obtained by the Fenton reagent at pH 3. The influence of pH, the water matrix and the catalyst/hydrogen peroxide concentration were investigated for the oxidation of toluene employing [FeCl2(bpmcn)] (1, bpmcn = N,N′-bis(2-pyridylmethyl)-N, N′-dimethyl-trans-1,2-diaminocyclohexane), the most efficient catalyst of the series. Moreover, the evolution of catalysts [FeCl2(bpmcn)] (1) and [Fe(OTf)2(Pytacn)] (3, Pytacn = 1-(2-pyridylmethyl)-4,7-dimethyl- 1,4,7-triazacyclononane, OTf = trifluoromethanesulfonate anion) during the course of the reaction was also studied by electrospray ionization mass spectrometry (ESI-MS). The oxidation products derived from toluene oxidation were also analyzed. A plausible mechanism of toluene degradation using [FeCl2(bpmcn)] (1) and [Fe(OTf)2(Pytacn)] (3) as catalysts was proposed, which involves the coexistence of a metal-based path, analogous to that operating in organic media where substrate oxidation is executed by an iron(V)-oxo-hydroxo species, in parallel to a Fenton-type process where hydroxyl radicals are formed.
KW - Olefin cis-dihydroxylation
KW - Hydrogen-peroxide
KW - Alkane hydroxylation
KW - Biphasic oxidation
KW - Waste-water
KW - C-h
KW - Degradation
KW - Toluene
KW - Destruction
KW - Epoxidation
UR - http://www.scopus.com/inward/record.url?scp=84883550492&partnerID=8YFLogxK
UR - https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=pure_univeritat_ramon_llull&SrcAuth=WosAPI&KeyUT=WOS:000330094700046&DestLinkType=FullRecord&DestApp=WOS_CPL
U2 - 10.1021/es401602t
DO - 10.1021/es401602t
M3 - Article
C2 - 23895017
AN - SCOPUS:84883550492
SN - 0013-936X
VL - 47
SP - 9918
EP - 9927
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 17
ER -