Mechanism of isotopic oxygen exchange and reduction of ferrate(VI) ion (FeO42-)

Abstract

k = 1.62 X 10-2 sec-1 at 25", log A = 9.51 =t 0.79, and E, = 15.4 & 1.0 kcal/mol. 6+ Fe is Fe02-and all oxygens are kinetically equivalent. celerated by dilute acid. HzO, HzOZ, and SO?-, and the results are compared with other strong oxidizing agents. and S03*-are quantitative and show simple stoichiometry. in S032-, but oxygen transfer from Fe042-to the product (02 or S042-) occurs only in the latter case.In basic media the rate of 1 8 0 exchange between Fe042-and water follows the law R = k[FeO4*-1, whereIn aqueous media the ion of Both water exchange and water oxidation are ac-Stoichiometric, kinetic, and 1 8 0 studies have been applied to the reaction of Fe02-withThe reaction with HZOZ The reactions are first order in Hz02 and second order ethods for preparing and analyzing potassium M ferrate, K2Fe04, of high purity (97-9973 have existed for some time, but little is known about its aqueous chemistry. K2Fe04(s) is usually prepared by strongly basic media and isolated from saturated KOH ~o l u t i o n .~-~ Electrolytic means may also be used.5Analysis consists of the oxidation of Cr(lI1) in basic media followed by titration of the Cr(V1) formed with Oc1-oxidation of freshly prepared iron hydroxide in (2) H.

Ferrate(VI) in the Treatment of Wastewaters: A New Generation Green Chemical

“…The tetrahedral structure was also confirmed by isotopic exchange study as performed in aqueous solutions [19]. The reliable simulated powder XRD patterns (ICSD file 2876 and 32756, [20]) and an experimental one (PDF file No.…”

“…The oxygen produced in this reaction showed the same isotopic composition as in the H 2 O 2 , which suggested that the O-O bond was retained in the oxidation of H 2 O 2 by ferrate(VI) [19].…”

“…In aqueous solution the ion Fe VI O 4 2-is monomeric with a high degree of four 'covalent character' equivalent oxygen atoms [19,22]. Potassium ferrate is insoluble in commonly used organic solvents and can be suspended in benzene, ether, chloroform etc.…”

“…These are well discussed in the following sections and summarized in the proceeding tables and figures. The reaction of Fe(VI) was categorized into two pathways, (i) its self decomposition (i.e., k S [Fe(VI)][Fe(VI)], reactions (15)(16)(17)(18)(19)(20), except (16)), and (ii) reaction with other compounds (i.e., k P [Fe(VI)][P]), which can be well conceptualized by the following reaction of rate expression:…”

“…The stoichiometries of the reactions between ferrate(VI) with hydrogen peroxide at pH 9.0 was presented (reaction (34)) [19].…”