Electrochemical carbon oxidation aqueous solutions

Zhang, J. and Oloman, C.W. (2005) Electro-oxidation of carbonate in aqueous solution on a platinum rotating disk electrode. J. Appl. Electrochem. 35, 945-953. 

However, while carbonaceous materials are abundant and therefore cheap, they also suffer from an insufficient long-term stability. Among the major issues hindering a commercial market launch of low-temperature polymer electrolyte membrane fuel cells (PEMFC), the poor durability of the carbon-supported catalysts appears to be the most critical [69,70]. In particular in the harsh conditions at the cathode side, severe corrosion of the carbon support takes place. Electrochemical oxidation of carbon in aqueous solution is already thermodynamically... 

Zou S, Gomes R, Weaver MJ. 1999. Infrared spectroscopy of carbon monoxide and nitric oxide on palladium(lll) in aqueous solution unexpected adlayer structural differences between electrochemical and ultrahigh-vacuum interfaces. J Electroanal Chem 474 155-166. 

Colbow, Zhang, and Wilkinson [128] showed that the performance of liquid feed fuel cells could be increased by oxidizing the carbon diffusion layer. The DL was electrochemically oxidized in acidic aqueous solution (impregnated in some cases with proton-conducting ionomer) prior to application of the electrocatalyst. 

Electrochemical oxidation of 2-, 3-, and 4-aminopyridines as well as 2,6-diaminopyridines and aminopicolines was studied in CH3CN-LiC104 by means of RDE voltammetry.422 Also, the electrochemical oxidation of 3-aminopyridine, 2,3-diaminopyridine, and 2,6-diaminopyridine has been investigated in aqueous solutions in the pH range 0.7-13 at platinum and carbon paste solid electrodes.423 A reaction scheme for the oxidation of aminopyridines was proposed on the basis of the voltammetric results, but the products of the oxidations were not identified. 

The electrochemical oxidation of NADH in aqueous solutions is seen as a single peak by cyclic voltammetry and takes place at 0.4, 0.7, and IV vs SCE at carbon, Pt, and Au electrodes, respectively (37,38). No re-reduction of NADH related intermediates is observed in cyclic voltammetry even at fast scan rates (30 V/s) (39), reflecting the high chemical irreversibility of the reaction. It was early recognized that the oxidation of NADH resulted in electrode fouling, necessitating... 

While these experiments, which were carried out without giving a theoretical insight into the nature of the electrochemical reaction, yielded almost all the possible oxidation products in the oxidation of methyl alcohol, Elbs and Brunner 2 have discovered a method which gives 80% of the current yield in formaldehyde. This is exactly the substance which could not be proven present up to that time among the electrolytic oxidation products of methyl alcohol. Elbs and Brunner electrolyzed an aqueous solution of 160 g. methyl alcohol and 49 to 98 g. sulphuric acid in a litre. They employed a bright platinum anode in an earthenware cylinder, using a current density of 3.75 amp.1 and a temperature of 30°. Only traces of formic acid and carbonic acid and a little carbon monoxide, aside from the 80 per cent, of formaldehyde, were formed. Plating the platinum anode with platinum decreased the yield of formaldehyde at the expense of the carbon dioxide. With an anode of lead peroxide the carbon dioxide exceeded the aldehyde. 

The possibility of reversible electron transfer within the modified DNA film was tested by carrying out an electrochemical study [85] of the redox couple Fe(lll)/Fe(Il) which has reasonably fast electrode kinetics, and which are dependent on electrode material. The oxidation of Fe(CN)g in 0.4 M K2S04 aqueous solution contacting the DNA-modified glassy carbon electrode showed virtually the same reaction rate as when using the bare glassy carbon electrode, Fig. 3.10, and the results were comparable to... 

The possible interactions and surface structures presented above (Schemes 11-13) describing copper species sorbed on various modified active carbon samples have been deduced from the results obtained. It seems that the dominant mechanisms of copper adsorption on heat-treated active carbon (D—H sample) could be dipole-dipole (n-d) interactions between graphene layers and metal ionic species and the spontaneous electrochemical reduction of copper ions. For oxidized active carbon samples (D—Ox, CWZ—Ox), surface ionization and the ion-exchange mechanism can describe cation sorption from aqueous solutions. 

Jannakoudakis, A.D., Jannakoudakis, P.D., Theodoridou, E., and Besenhard, J.O. (1990). Electrochemical oxidation of carbon fibers in aqueous solutions and analysis of the surface oxides. J. Appl. Electrochem., 20, 619-24. 

Harry, I.D., Saha, B., and Cumming, I.W.. Effect of electrochemical oxidation of activated carbon fiber on competitive and noncompetitive sorption of trace toxic metal ions from aqueous solution, J. Colloid Interf. Sci., 304, 9, 2006. 

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