Kinetics of the methylene blue oxidation by cerium(iv) in sulphuric acid solutions

A. Katafias, P. Kita, G. Wrzeszcz, A. Mills

Research output: Contribution to journalArticle

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Abstract

The oxidation of methylene blue (MB+) by cerium(IV) was studied in 0.1-5 M H2SO4. The reaction proceeds via MB radical (MB2+•) formed by one electron transfer to the oxidant. The radical is observed spectrophotometrically by a very intense absorbance at λmax = 526 nm and by the e.p.r signal at g = 2.000. The kinetics of the fast radical formation are two orders of magnitude slower than its decomposition, which were examined using a stopped-flow method at 298 K under pseudo-first order conditions. The rate laws for the both steps were determined and a likely mechanism reported.
Original languageEnglish
Pages (from-to)31-37
Number of pages6
JournalTransition Metal Chemistry
Volume32
Issue number1
DOIs
Publication statusPublished - Feb 2007

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Cerium
Methylene Blue
Oxidants
Decomposition
Oxidation
Kinetics
Acids
Electrons

Keywords

  • methylene blue oxidation
  • cerium
  • protolytic equilibria
  • protolytic equilibrium
  • electron transfer
  • redox reactions
  • oxidation

Cite this

Katafias, A. ; Kita, P. ; Wrzeszcz, G. ; Mills, A. / Kinetics of the methylene blue oxidation by cerium(iv) in sulphuric acid solutions. In: Transition Metal Chemistry. 2007 ; Vol. 32, No. 1. pp. 31-37.
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Kinetics of the methylene blue oxidation by cerium(iv) in sulphuric acid solutions. / Katafias, A.; Kita, P.; Wrzeszcz, G.; Mills, A.

In: Transition Metal Chemistry, Vol. 32, No. 1, 02.2007, p. 31-37.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Kinetics of the methylene blue oxidation by cerium(iv) in sulphuric acid solutions

AU - Katafias, A.

AU - Kita, P.

AU - Wrzeszcz, G.

AU - Mills, A.

PY - 2007/2

Y1 - 2007/2

N2 - The oxidation of methylene blue (MB+) by cerium(IV) was studied in 0.1-5 M H2SO4. The reaction proceeds via MB radical (MB2+•) formed by one electron transfer to the oxidant. The radical is observed spectrophotometrically by a very intense absorbance at λmax = 526 nm and by the e.p.r signal at g = 2.000. The kinetics of the fast radical formation are two orders of magnitude slower than its decomposition, which were examined using a stopped-flow method at 298 K under pseudo-first order conditions. The rate laws for the both steps were determined and a likely mechanism reported.

AB - The oxidation of methylene blue (MB+) by cerium(IV) was studied in 0.1-5 M H2SO4. The reaction proceeds via MB radical (MB2+•) formed by one electron transfer to the oxidant. The radical is observed spectrophotometrically by a very intense absorbance at λmax = 526 nm and by the e.p.r signal at g = 2.000. The kinetics of the fast radical formation are two orders of magnitude slower than its decomposition, which were examined using a stopped-flow method at 298 K under pseudo-first order conditions. The rate laws for the both steps were determined and a likely mechanism reported.

KW - methylene blue oxidation

KW - cerium

KW - protolytic equilibria

KW - protolytic equilibrium

KW - electron transfer

KW - redox reactions

KW - oxidation

UR - http://dx.doi.org/10.1007/s11243-006-0120-3

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DO - 10.1007/s11243-006-0120-3

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