Electrocatalytic Degradation of Cellulose Using Lead Dioxide Anode

2011 ◽  
Vol 233-235 ◽  
pp. 1036-1039 ◽  
Author(s):  
De Fa Meng ◽  
Gang Li ◽  
Fang Yang ◽  
Zhi Hua Liu
Keyword(s):  
Cellulose Degradation ◽  
Lead Dioxide ◽  
Soluble Sugar ◽  
Saturated Calomel Electrode ◽  
Electrode System ◽  
Capillary Viscometer ◽  
Electrocatalytic Degradation ◽  
Lead Dioxide Anode ◽  
Ft Ir ◽  
Sulfuric Acid Method

A novel method of cellulose degradation is investigated in this paper. In this work, a three-electrode system, which contains a Pb/PbO2 anode, two copper cathodes and a reference saturated calomel electrode (SCE), is applied to electrocatalytic degradation of cellulose. The composition of the products in filtrate is characterized by phenol-sulfuric acid method, NMR and GC-MS. In addition, the solid sample is analyzed via Ubbelohde capillary viscometer and FT-IR spectra. The results suggest that it is effective to convert cellulose to soluble sugar, 5-hydroxymethylfurfural (5-HMF) and other products by electrocatalytic method. The reaction mechanism of cellulose degradation is also discussed.

The Lead Dioxide Anode. II. The Kinetics and Participation of the Lead Dioxide Electrode in Electrochemical Oxidation Reactions in Sulfuric Acid

1989 ◽  
Vol 42 (9) ◽  
pp. 1527 ◽  
Author(s):  
TH Randle ◽  
AT Kuhn
Keyword(s):  
Sulfuric Acid ◽  
Electrochemical Oxidation ◽  
Maximum Rate ◽  
Lead Dioxide ◽  
Chemical Oxidation ◽  
Oxidation Reactions ◽  
Electrochemical Regeneration ◽  
Electrode Surfaces ◽  
Lead Dioxide Electrode ◽  
Lead Dioxide Anode

Lead dioxide is a strong oxidizer in sulfuric acid, consequently electrochemical oxidation of solution species at a lead dioxide anode may occur by a two-step, C-E process (chemical oxidation of solution species by PbO2 followed by electrochemical regeneration of the reduced lead dioxide surface). The maximum rate of each step has been determined in sulfuric acid for specified lead dioxide surfaces and compared with the rates observed for the electrochemical oxidation of cerium(III) and manganese(II) on the same electrode surfaces. While the rate of electrochemical oxidation of a partially reduced PbO2 surface may be sufficient to support the observed rates of CeIII and MnII oxidation at the lead dioxide anode, the rate of chemical reaction between PbO2 and the reducing species is not. Hence it is concluded that the lead dioxide electrode functions as a simple, 'inert' electron-transfer agent during the electrochemical oxidation of CellI and MnII in sulfuric acid. In general, it will most probably be the rate of the chemical step which determines the feasibility or otherwise of the C-E mechanism.

Lead Dioxide Anode for Commercial Use

1958 ◽  
Vol 105 (2) ◽  
pp. 100 ◽  
Author(s):  
J. C. Grigger ◽  
H. C. Miller ◽  
F. D. Loomis
Keyword(s):  
Lead Dioxide ◽  
Commercial Use ◽  
Lead Dioxide Anode

scholarly journals Synthesis, Structures, Electrochemistry, and Catalytic Activity towards Cyclohexanol Oxidation of Mono-, Di-, and Polynuclear Iron(III) Complexes with 3-Amino-2-Pyrazinecarboxylate

2020 ◽  
Vol 10 (8) ◽  
pp. 2692
Author(s):  
Anirban Karmakar ◽  
Luísa M.D.R.S. Martins ◽  
Yuliya Yahorava ◽  
M. Fátima C. Guedes da Silva ◽  
Armando J. L. Pombeiro
Keyword(s):  
Coordination Polymer ◽  
Heterogeneous Catalysts ◽  
Saturated Calomel Electrode ◽  
Two Dimensional ◽  
Reaction Conditions ◽  
Ability To Act ◽  
Tert Butyl Hydroperoxide ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

The synthesis and characterization of a set of iron(III) complexes, viz. the mononuclear [Fe(L)3] (1) and [NHEt3][Fe(L)2(Cl)2] (2), the dinuclear methoxido-bridged [Fe(L)2(μ-OMe)]2.DMF.1.5MeOH (3), and the heteronuclear Fe(III)/Na(I) two-dimensional coordination polymer [Fe(N3)(μ-L)2(μ-O)1/2(Na)(μ-H2O)1/2]n (4), are reported. Reactions of 3-amino-2-pyrazinecarboxylic acid (HL) with iron(III) chloride under different reaction conditions were studied, and the obtained compounds were characterized by elemental analysis, Fourier Transform Infrared (FT-IR) spectroscopy, and X-ray single-crystal diffraction. Compound 1 is a neutral mononuclear complex, whereas 2 is mono-anionic with its charge being neutralized by triethylammonium cation. Compounds 3 and 4 display a di-methoxido-bridged dinuclear complex and a two-dimensional heterometallic Fe(III)/Na(I) polynuclear coordination polymer, respectively. Compounds 3 and 4 are the first examples of methoxido- and oxido-bridged iron(III) complexes, respectively, with 3-amino-2-pyrazinecarboxylate ligands. The electrochemical study of these compounds reveals a facile single-electron reversible Fe(III)-to-Fe(II) reduction at a positive potential of 0.08V vs. saturated calomel electrode (SCE), which is in line with their ability to act as efficient oxidants and heterogeneous catalysts for the solvent-free microwave-assisted peroxidative oxidation (with tert-butyl hydroperoxide) of cyclohexanol to cyclohexanone (almost quantitative yields after 1 h). Moreover, the catalysts are easily recovered and reused for five consecutive cycles, maintaining a high activity and selectivity.

The Lead Dioxide Anode. I. A Kinetic Study of the Electrolytic Oxidation of Cerium(III) and Manganese(II) in Sulfuric Acid at the Lead Dioxide Electrode

1989 ◽  
Vol 42 (2) ◽  
pp. 229 ◽  
Author(s):  
TH Randle ◽  
AT Kuhn
Keyword(s):  
Sulfuric Acid ◽  
Platinum Electrode ◽  
Lead Dioxide ◽  
Chemical Oxidation ◽  
Oxidation Reactions ◽  
Heterogeneous Chemical ◽  
Lead Dioxide Anode ◽  
Direct Support ◽  
Electrolytic Oxidation ◽  
Step Mechanism

The electrolytic oxidation reactions of cerium(III) and manganeseII) in sulfuric acid have been used as probes to investigate the mechanism of the lead dioxide anode. The kinetics observed for such reactions at the lead dioxide surface provide no direct support for the proposal that the lead dioxide anode functions by a sequential 'two-step' mechanism (heterogeneous chemical oxidation of solution species followed by electrochemical oxidation of the reduced lead dioxide surface); rather the kinetics show characteristics similar to those observed previously for the oxidation of cerium(III) and manganese(II) at the platinum electrode, suggesting that the lead dioxide surface functions as a simple, 'inert' electron-transfer agent.

Oxygen overpotential of graphite-substrate lead dioxide anode

1965 ◽  
Vol 10 (12) ◽  
pp. 1185-1187 ◽  
Author(s):  
M.S.V. Pathy ◽  
H.V.K. Udupa
Keyword(s):  
Lead Dioxide ◽  
Graphite Substrate ◽  
Lead Dioxide Anode

Electrocatalytic degradation kinetic of 4-chlorophenol by the Pd/C gas-diffusion electrode system

2013 ◽  
Vol 67 (8) ◽  
pp. 1873-1879 ◽  
Author(s):  
Z. Y. Bian ◽  
Y. Bian ◽  
H. Wang ◽  
L. Pang ◽  
A. Z. Ding
Keyword(s):  
Electrochemical Oxidation ◽  
Reduction Process ◽  
Degradation Process ◽  
Electrochemical Reactor ◽  
Gas Diffusion ◽  
Electrode System ◽  
Accurate Estimation ◽  
Degradation Kinetic ◽  
Effluent Concentration ◽  
Electrocatalytic Degradation

A Pd/C gas-diffusion cathode which generated H2O2 through a two-electron reduction process of fed oxygen molecule was used to degrade 4-chlorophenol in an undivided electrolysis device. The kinetics of 4-chlorophenol degradation has been investigated by the electrochemical oxidation processes. By inspecting the relationship between the rate constants (k) and influencing factors, using first-order kinetics to describe the electrochemical oxidation process of 4-chlorophenol, a kinetic model of 4-chlorophenol degradation process was proposed to calculate the 4-chlorophenol effluent concentration: C = C0 exp( -3:76 × 10-6C-0.50J2M-0.7Q0.17Dt). It was found that the electrocatalytic degradation rate of 4-chlorophenol was affected by current density, electrode distance, air-feeding rate, electrolyte concentration and initial 4-chlorophenol concentration. The kinetics obtained from the experiments under corresponding electrochemical conditions could provide an accurate estimation of 4-chlorophenol effluent concentration and lead to better design of the electrochemical reactor.

The effect of Cobalt on the Kinetics of Oxygen evolution at a Lead Dioxide anode in Sulphuric Acid

1959 ◽  
Vol 12 (2) ◽  
pp. 127 ◽  
Author(s):  
DFA Koch
Keyword(s):  
Sulphuric Acid ◽  
Oxygen Evolution ◽  
Current Density ◽  
Lead Dioxide ◽  
Kinetic Constants ◽  
Kcal Mole ◽  
Lead Dioxide Anode ◽  
Kinetics Of ◽  
Evolution Of Oxygen ◽  
Rate Determining Steps

The overpotential (n)-log current density (log i) curves for the evolution of oxygen at a lead dioxide anode in 2N H2SO4 both in the absence and presence of cobaltous sulphate in solution have been used to determine the electrode kinetic constants α ; i0 for a series of temperatures and also ΔH0*:. At 25 �C in the absence of cobalt α=O.59, i0= 10-11, and ΔH0*= 15 kcal mole-1 When 13 mg/l cobaltous sulphate is added α= 1.0, i0= 10-15, and ΔH0*:=29 kcal mole-1. Possible mechanisms for the reaction are discussed on the basis of these values and the rate determining steps suggested (where M represents the PbO2 surface) are M +H2O =MOH +H+ +e in the absence of cobalt and 2CoOH++ = 2Co++ +H2O + O in its presence.

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