Kinetics of the uninhibited and ethanol-inhibited CoO, Co2O3 and Ni2O3 catalyzed autoxidation of sulfur(IV) in alkaline medium

Gupta, K. C.; Mehta, R. K.; Sharma, Anil Kumar; Mudgal, Punit K.; Bansal, Seema

doi:10.1007/s11243-008-9115-6

Cited by 16 publications

(6 citation statements)

References 30 publications

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“…S(IV), were studied by following the decrease in the concentration of S(IV). This procedure was the same as that described by Brodizinsky et al [42] and subsequently used by us [43][44][45][46]. The reactions were conducted in 0.15 L Erlenmeyer flasks open to air, to allow the passage of atmospheric oxygen.…”

Section: Methodsmentioning

confidence: 99%

Inhibition of Atmospheric Aqueous Phase Autoxidation of Sulphur Dioxide by Volatile Organic Compounds: Mono-, di- and Tri-Substituted Benzenes and Benzoic Acids

Meena

Dhayal

Rathore

et al. 2017

Progress in Reaction Kinetics and Mechanism

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Like many other volatile organic compounds (VOCs), the methoxy derivatives of benzene and benzoic acid are found in the atmosphere and, therefore, looking to their possible intervention in aqueous phase atmospheric oxidation of the major acid rain precursor, SO2, by oxygen, the kinetics of SO2 [hereafter referred to as S(IV)] autoxidation have been studied in the presence of methoxybenzene (anisole) and disubstituted 1,2-dimethoxybenzene, 1,3-dimethoxybenzene and 1,4-dimethoxybenzene. The effects of benzoic acid and its 2,6-dimethoxy, 3,4-dimethoxy, 2,3,4-trimethoxy and 2,4,5-trimethoxy derivatives have also been examined, as have the influences of 4-hydroxybenzoic acid, benzanilide and o-sulfobenzimide. As the methoxy group is known to influence the reaction SO4–· + organics [Formula: see text] SO42– + non-chain products, to understand the degree of influence of the methoxy group on the inhibition of this reaction, this series of methoxy compounds was selected. The kinetics were first-order in S(IV). Most of the VOCs inhibited S(IV) autoxidation, except benzanilide and o-sulfobenzimide, in accordance with kobs = k0/(1 + B [Inh]), where kobs and k0 are the first-order rate constants in the presence and absence of VOCs respectively and B is the inhibition parameter. The most interesting feature of this work is that, despite the high kinh values, the B values are unexpectedly quite low and benzanilide and o-sulfobenzimide showed no effect. The B values appear to be independent of kinh, which is opposite to that found in the case of a series of hydroxyl compounds. It appears probable that additional steps involving peroxy intermediates are involved.

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Section: Methodsmentioning

confidence: 99%

Inhibition of Atmospheric Aqueous Phase Autoxidation of Sulphur Dioxide by Volatile Organic Compounds: Mono-, di- and Tri-Substituted Benzenes and Benzoic Acids

Meena

Dhayal

Rathore

et al. 2017

Progress in Reaction Kinetics and Mechanism

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“…The high reactivity of Co/Cr surfaces toward oxygen plays a key role in technological applications, ranging from perpendicular magnetic recording media 10,11 to orthopedic implants 12 and heterogeneous catalysis. 13,14 In particular, Cr is one of the most established alloying elements for corrosion protection.…”

Section: Introductionmentioning

confidence: 99%

Mechanisms of Initial Oxidation of the Co(0001) and Cr(110) Surfaces

Zimmermann

Ciacchi

2010

J. Phys. Chem. C

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Despite the fundamental importance of metal surface oxidation in a number of emerging fields such as catalysis, microelectronics, and biosensor technology, a comprehensive picture of the processes leading to the growth of thin oxide layers at low temperature is still lacking. In this work, we employ advanced first-principles molecular dynamics based on density-functional theory to investigate the early oxidation stages of the Co(0001) and Cr(110) surfaces and observe surprisingly different chemical mechanisms governed by a delicate balance between thermodynamical and kinetic effects. On cobalt, oxide nucleation occurs via an early place-exchange of the metal atoms of the surface layer with oxygen atoms of dissociatively adsorbing O2 molecules. Further development of the oxide takes place according to a kinetically constrained reaction path, which leads to pseudoamorphous structures bearing evident Co3O4-like magnetic, electronic and structural properties. These results help to rationalize a number of low-temperature experimental data for the (0001) and other Co surface orientations. In contrast, chromium oxidizes along a thermodynamically stable path involving the formation of perfect oxygen ad-layers, which strongly reduce the reactivity of the surface toward further oxygen adsorption. Only the thermally activated extraction of Cr atoms off the metal surface and the unexpected formation of chromate-like precursory structures initiates the experimentally observed layer-by-layer growth of epitaxial Cr2O3 oxide films.

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“…Prasad & Gupta et al [11,37] proposed a similar mechanism for the Co 2 O 3 and CoO catalysed autoxidation of SO 2 inhibited by formic acid and ethanol respectively, which lead to the same rate law. By comparing derived rate law with the experimental rate law we observe the similarity in these two.…”

Section: Hso H Somentioning

confidence: 95%

“…The rate of uncatalysed and Ag(I) catalysed reaction is decelerated by the addition of aniline in the present study. Gupta et al [37] reported that radical mechanism operate in those reaction in which the inhibition parameters lies 10 3 -10 4 In the present study the value of inhibition parameter for uncatalysed and Ag(I) catalysed autoxidation of S(IV) by anilineare found to be in the range 10 3 -10 4 These values are in the same range as reported by Gupta et al [37] This is strongly support the radical mechanism in the present case too based on the observed results. The free radical mechanism is very complex, the present work close to the experimental condition of Connick et al [38].…”

Section: Hso H Somentioning

confidence: 99%

The Inhibitive Action of Aniline on the Autoxidation of Sodium Sulfite in Acidic Medium

Sharma¹

2017

JAPLR

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The kinetics of atmospheric autoxidation of S (IV) by Ag(I) at pH 4.02-5.25 has been studied. The aqueous phase autoxidation of S (IV) is the major factor responsible for acidification of atmospheric aqueous system. The role of Aniline act as an inhibitor of Ag(I) catalysed autoxidation of S(IV) in acidic medium has been identified, and based on the observed results following rate law given and a free radical mechanism has been proposed.( )

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Kinetics of the uninhibited and ethanol-inhibited CoO, Co2O3 and Ni2O3 catalyzed autoxidation of sulfur(IV) in alkaline medium

Cited by 16 publications

References 30 publications

Inhibition of Atmospheric Aqueous Phase Autoxidation of Sulphur Dioxide by Volatile Organic Compounds: Mono-, di- and Tri-Substituted Benzenes and Benzoic Acids

Inhibition of Atmospheric Aqueous Phase Autoxidation of Sulphur Dioxide by Volatile Organic Compounds: Mono-, di- and Tri-Substituted Benzenes and Benzoic Acids

Mechanisms of Initial Oxidation of the Co(0001) and Cr(110) Surfaces

The Inhibitive Action of Aniline on the Autoxidation of Sodium Sulfite in Acidic Medium

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