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methanol-electro-oxidation
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A study of the electro-catalytic oxidation of methanol on a cobalt hydroxide modified glassy carbon electrode
, Article Electrochimica Acta ; Volume 48, Issue 23 , 2003 , Pages 3423-3429 ; 00134686 (ISSN) ; Mahjani, M. G ; Heli, H ; Gobal, F ; Khajehsharifi, H ; Hamedi, M. H ; Sharif University of Technology
2003
Abstract
Cobalt hydroxide modified glassy carbon electrodes (CHM/GC) prepared by the anodic deposition in presence of tartrate ions have been used for the electro-catalytic oxidation of methanol in alkaline solutions where the methods of cyclic voltammetery (CV), chronoamperometry (CA) and impedance spectroscopy (IS) have been employed. In CV studies, in the presence of methanol the peak current of the oxidation of cobalt hydroxide increase is followed by a decrease in the corresponding cathodic current. This suggests that the oxidation of methanol is being catalysed through the mediated electron transfer across the cobalt hydroxide layer comprising of cobalt ions of various valence states. A...
The Poisoning Effect of Sulfur-Containing Compounds on the Elelctro-Oxidation of Methanol and Ethanol on Ni and Cu Electrodes
, M.Sc. Thesis Sharif University of Technology ; Gobal, Fereydon (Supervisor)
Abstract
In this study a systematic effort was made to investigate the poisoning effect of sulfur-containing materials on the electro- oxidation of methanol and ethanol on Ni and Cu electrodes in alkaline solutions by the methods of cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. Activation energy of methanol electro-oxidation in the absence of Na2S was obtained 30.7 kJ/mol by cyclic voltammetric at different temperatures, and its values increased by increase in Na2S concentrations to 97kJ/mol. Na2S adsorption isotherms corresponded with Langmuire isotherm, equilibrium constants of adsorption – desorption and adsorption enthalpy (ΔHads= -62kJ/mol) were calculated for...
Modification of Electrode Substrates Using Nanocomposites Including Carbon Nanomaterials and Multimetallic Nanoparticles for Electrocatalysis of some Fuel Cells Reactions
, Ph.D. Dissertation Sharif University of Technology ; Shahrokhian, Saeed (Supervisor)
Abstract
In this research, nanocomposite containing reduced graphene oxide nanosheets (RGO) and trimetallic three-dimensional (3D) Pt-Pd-Co porous nanostructures was fabricated by galvanic replacement technique. First, GO suspension was drop-casted on the electrode surface, then GO film reduction was carried out by cycling the potential in negative direction to form the RGO on GCE (RGO/GCE). Then, electrodeposition of the cobalt nanoparticles (CoNPs) as sacrificial seeds was performed onto the RGO/GCE by using cyclic voltammetry. Afterward, Pt-Pd-Co 3D porous nanostructures fabrication occurs through galvanic replacement method based on a spontaneous redox process between CoNPs and solution...
On the significance of hydroxide ion in the electro-oxidation of methanol on Ni
, Article Journal of Electroanalytical Chemistry ; Volume 650, Issue 2 , January , 2011 , Pages 219-225 ; 15726657 (ISSN) ; Valadbeigi, Y ; Kasmaee, L. M ; Sharif University of Technology
2011
Abstract
Electro-oxidation of methanol on Ni in NaOH solutions with the alkali concentration in the range of 0.05-0.5 M and in the presence of 0.5 M Na 2SO4 supporting electrolyte is studied. All the mentioned species compete for adsorption on Ni and OH- is essential for the electro-oxidation process. The electro-oxidation seems to proceed through the electro-chemical reactions of adsorbed methanol and hydroxide species and the removal of the resulting intermediate by adsorbed hydroxyl groups. The mechanism is consistent with the cyclic voltammetry and impedance spectroscopy results and can semi-quantitatively account for the appearance of capacitive, inductive and negative resistance loops as well...
Synergistic effect of cobalt and copper on a nickel-based modified graphite electrode during methanol electro-oxidation in NaOH solution
, Article Cuihua Xuebao/Chinese Journal of Catalysis ; Volume 36, Issue 11 , 2015 , Pages 1867-1874 ; 02539837 (ISSN) ; Jafarian, M ; Miandari, S ; Mahjani, M. G ; Gobal, F ; Sharif University of Technology
Abstract
The electrocatalytic oxidation of methanol was studied over Ni, Co and Cu binary or ternary alloys on graphite electrodes in a NaOH solution (0.1 mol/L). The catalysts were prepared by cycling the graphite electrode in solutions containing Ni, Cu and Co ions at cathodic potentials. The synergistic effects and catalytic activity of the modified electrodes were investigated by cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS). It was found that, in the presence of methanol, the modified Ni-based ternary alloy electrode (G/NiCuCo) exhibited a significantly higher response for methanol oxidation compared to the other samples. The anodic peak...