Platinized platinum, voltammetric

It was demonstrated that the radiotracer method, using labeled anions, is an adequate tool to follow anion adsorption in the course of voltammetric measurements and to gain simultaneous information on hydrogen and anion adsorption [163]. Coupling voltammetric and radiometric measurements in the study of platinized platinum electrodes gave insight in the anion-hydrogen atom coadsorption process. 

The basicity of a number of reagents 1, 5 and related compounds in THF solutions was determined voltammetrically by Chevrot and coworkers . Using platinized platinum and hydrogen electrodes, they measured the cathodic-anodic current as a function of potential for overall electrode reactions (equations 43a and 43b)... 

A mechanically polished tin disk immersed in 0.5 M citric acid was prepared following the procedure described in the literature [59]. Because high-scan-rate voltammetric curves were recorded, a calomel reference electrode is not recommended because of its slow response [60], The reversible hydrogen electrode (RHE) was used as the reference electrode at 25°C. The required materials and reagents are a three-compartment electrochemical cell with a platinized platinum auxiliary electrode and a 0.5 M (pH = 1.8) citric acid solution prepared with triple-distilled water. 

Actually, the results of a comparative study of the voltammetric behavior of NO3 ion at a platinized platinum electrode with (100) preferred orientation and at a polycrystalline one prove the higher catalytic activity of the former system over the latter one, as expected on the basis of single crystal studies. It should be mentioned that this kind of difference was not found in the reduction of CIO4. 

Sobkowski, J. and A. Czerwinski. 1985. Voltammetric study of carbon monoxide and carbon dioxide adsorption on smooth and platinized platinum electrodes. /. Phys. Chem. 89 365-369. 

The similarity of the shape of the voltammetric curves of platinized system to those reported for electrodes treated by the fast repetitive potential perturbation technique or obtained by annealing electrodeposited platinum and the appearance of signs characteristic for stepped surfaces allows us to assume that these phenomena should be ascribed to the similarities in the surface structure. 

FIGURE 2.25 Voltammetric responses of a platinum electrode in superdry DMF containing 0.1 mol.L TMACIO4. Scan rate 0.1 Vs". Apparent electrode area 0.8 10 cm. Potentials are referred to the SCE electrode. Platinized electrode (area of platinum substrate 0.8 10 cm ) with a plating of average thickness of 8 = 0.1 pm. In the insert, chronoamperometric curve with a reduction at —2.6 V (10 s) followed by an oxidation at -0.5 V is shown. (Simonet, J., 2006, J. Electroanal. Chem. 93 3. Used with permission.)... 

The question of the nature of the oxygen electrode in molten nitrates has been quite recently reopened by Temple and co-workers,who state that potentiometric results at platinized electrodes are in agreement with the reaction + 2e 0. These results imply a greater stability for the oxide ions in molten nitrates than that arising from the studies of Zambonin and Jordan.It appears that further work will be needed to resolve this controversy. One reason for the discrepancy between potentiometric and voltammetric (chronopotentiometric) results in nitrates may be the different electrochemical behavior of platinized (used for potentiometric work) and bright (used for voltammetric studies) platinum. 

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