Kinetics and mechanism of o-aminophenol oxidation by the supported mesoporous silica (HISiO2) in the binary system with Amberlite resin

S. A. El-Safty, J. Evans, M. Y. El-Sheikh, A. B. Zaki

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

HISiO2 (hexagonal mesoporous silica) was synthesized with a high concentration of a non-ionic template. The synthesized HISiO2 materials have a well defined porous architecture with surface area (760 m2 g-1), and pore size=35 Å. Cu(II)-aquo complex was anchored onto silica (S-CuII) through the coordination with amino-functionalized HISiO2 (S-NH2) without impregnation on the surface. The oxidation of o-aminophenol (o-AP) with (S-CuII), Cu(II)-oxalate complex supported on Amberlite resin (R-CuII), (R-CuII)/S-NH2 (0.05 g), and a mixture (1:1) of (R-CuII)/(S-CuII), has been studied at different temperatures (25-40°C) ±0.1. The oxidation product has been monitored kinetically and spectrophotometrically. All redox reactions were characterized by first-order kinetics. The rate constant of the oxidation reaction of o-AP decreases in the following order; (S-CuII)>(R-CuII)/(S-CuII)>(R-Cu II)/(S-NH2)>(R-CuII). This sequence reflects the role of the effective surface area of HISiO2 on the redox reaction. The activation parameters for the amine oxidation have been estimated. Besides, a mechanism of the oxidation process of o-AP has been proposed.

Original languageEnglish
Pages (from-to)217-228
Number of pages12
JournalColloids and Surfaces A: Physicochemical and Engineering Aspects
Volume203
Issue number1-3
DOIs
Publication statusPublished - 2002 Apr 25
Externally publishedYes

Fingerprint

Amberlite (trademark)
Silicon Dioxide
resins
Resins
Silica
silicon dioxide
Oxidation
oxidation
Kinetics
kinetics
Redox reactions
Oxalates
oxalates
Impregnation
Pore size
Amines
Porous materials
Rate constants
amines
templates

Keywords

  • Amberlite anion-exchanger
  • Copper-complexes
  • Hexagonal mesoporous silica
  • Kinetics
  • O-Aminophenol
  • Oxidation
  • Synthesis

ASJC Scopus subject areas

  • Colloid and Surface Chemistry
  • Physical and Theoretical Chemistry

Cite this

Kinetics and mechanism of o-aminophenol oxidation by the supported mesoporous silica (HISiO2) in the binary system with Amberlite resin. / El-Safty, S. A.; Evans, J.; El-Sheikh, M. Y.; Zaki, A. B.

In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, Vol. 203, No. 1-3, 25.04.2002, p. 217-228.

Research output: Contribution to journalArticle

@article{10c50fd3ba7c4686aecc1c43771d1cd5,
title = "Kinetics and mechanism of o-aminophenol oxidation by the supported mesoporous silica (HISiO2) in the binary system with Amberlite resin",
abstract = "HISiO2 (hexagonal mesoporous silica) was synthesized with a high concentration of a non-ionic template. The synthesized HISiO2 materials have a well defined porous architecture with surface area (760 m2 g-1), and pore size=35 {\AA}. Cu(II)-aquo complex was anchored onto silica (S-CuII) through the coordination with amino-functionalized HISiO2 (S-NH2) without impregnation on the surface. The oxidation of o-aminophenol (o-AP) with (S-CuII), Cu(II)-oxalate complex supported on Amberlite resin (R-CuII), (R-CuII)/S-NH2 (0.05 g), and a mixture (1:1) of (R-CuII)/(S-CuII), has been studied at different temperatures (25-40°C) ±0.1. The oxidation product has been monitored kinetically and spectrophotometrically. All redox reactions were characterized by first-order kinetics. The rate constant of the oxidation reaction of o-AP decreases in the following order; (S-CuII)>(R-CuII)/(S-CuII)>(R-Cu II)/(S-NH2)>(R-CuII). This sequence reflects the role of the effective surface area of HISiO2 on the redox reaction. The activation parameters for the amine oxidation have been estimated. Besides, a mechanism of the oxidation process of o-AP has been proposed.",
keywords = "Amberlite anion-exchanger, Copper-complexes, Hexagonal mesoporous silica, Kinetics, O-Aminophenol, Oxidation, Synthesis",
author = "El-Safty, {S. A.} and J. Evans and El-Sheikh, {M. Y.} and Zaki, {A. B.}",
year = "2002",
month = "4",
day = "25",
doi = "10.1016/S0927-7757(01)01102-5",
language = "English",
volume = "203",
pages = "217--228",
journal = "Colloids and Surfaces A: Physicochemical and Engineering Aspects",
issn = "0927-7757",
publisher = "Elsevier",
number = "1-3",

}

TY - JOUR

T1 - Kinetics and mechanism of o-aminophenol oxidation by the supported mesoporous silica (HISiO2) in the binary system with Amberlite resin

AU - El-Safty, S. A.

AU - Evans, J.

AU - El-Sheikh, M. Y.

AU - Zaki, A. B.

PY - 2002/4/25

Y1 - 2002/4/25

N2 - HISiO2 (hexagonal mesoporous silica) was synthesized with a high concentration of a non-ionic template. The synthesized HISiO2 materials have a well defined porous architecture with surface area (760 m2 g-1), and pore size=35 Å. Cu(II)-aquo complex was anchored onto silica (S-CuII) through the coordination with amino-functionalized HISiO2 (S-NH2) without impregnation on the surface. The oxidation of o-aminophenol (o-AP) with (S-CuII), Cu(II)-oxalate complex supported on Amberlite resin (R-CuII), (R-CuII)/S-NH2 (0.05 g), and a mixture (1:1) of (R-CuII)/(S-CuII), has been studied at different temperatures (25-40°C) ±0.1. The oxidation product has been monitored kinetically and spectrophotometrically. All redox reactions were characterized by first-order kinetics. The rate constant of the oxidation reaction of o-AP decreases in the following order; (S-CuII)>(R-CuII)/(S-CuII)>(R-Cu II)/(S-NH2)>(R-CuII). This sequence reflects the role of the effective surface area of HISiO2 on the redox reaction. The activation parameters for the amine oxidation have been estimated. Besides, a mechanism of the oxidation process of o-AP has been proposed.

AB - HISiO2 (hexagonal mesoporous silica) was synthesized with a high concentration of a non-ionic template. The synthesized HISiO2 materials have a well defined porous architecture with surface area (760 m2 g-1), and pore size=35 Å. Cu(II)-aquo complex was anchored onto silica (S-CuII) through the coordination with amino-functionalized HISiO2 (S-NH2) without impregnation on the surface. The oxidation of o-aminophenol (o-AP) with (S-CuII), Cu(II)-oxalate complex supported on Amberlite resin (R-CuII), (R-CuII)/S-NH2 (0.05 g), and a mixture (1:1) of (R-CuII)/(S-CuII), has been studied at different temperatures (25-40°C) ±0.1. The oxidation product has been monitored kinetically and spectrophotometrically. All redox reactions were characterized by first-order kinetics. The rate constant of the oxidation reaction of o-AP decreases in the following order; (S-CuII)>(R-CuII)/(S-CuII)>(R-Cu II)/(S-NH2)>(R-CuII). This sequence reflects the role of the effective surface area of HISiO2 on the redox reaction. The activation parameters for the amine oxidation have been estimated. Besides, a mechanism of the oxidation process of o-AP has been proposed.

KW - Amberlite anion-exchanger

KW - Copper-complexes

KW - Hexagonal mesoporous silica

KW - Kinetics

KW - O-Aminophenol

KW - Oxidation

KW - Synthesis

UR - http://www.scopus.com/inward/record.url?scp=0037171530&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037171530&partnerID=8YFLogxK

U2 - 10.1016/S0927-7757(01)01102-5

DO - 10.1016/S0927-7757(01)01102-5

M3 - Article

AN - SCOPUS:0037171530

VL - 203

SP - 217

EP - 228

JO - Colloids and Surfaces A: Physicochemical and Engineering Aspects

JF - Colloids and Surfaces A: Physicochemical and Engineering Aspects

SN - 0927-7757

IS - 1-3

ER -