Platinum oxide film formation

Birss VI, Chang M, Segal J. 1993. Platinum oxide film formation reduction— An in-situ mass measurement study. J Electroanal Chem 355 181-191. 

Tremiliosi-Eilho G, Jerkiewicz G, Conway BE. 1992. Characterization and significance of the sequence of stages of oxide film formation at platinum generated by strong anodic polarization. Langmuir 8 658-667. 

As for the mechanism of the Pt(02) gas electrode s work in the nitrate melt, the authors of Ref. [225] found it to become metal-oxide owing to the formation of a platinum oxide film on the electrode surface. 

Antimony (III) interferes with the electrolysis under certain conditions, possibly because of the formation of Sb204 at the electrode surface rendering it passive to further oxidation of arsenic. Prepolarization of the platinum electrodes appeared to be of some consequence arsenic (III) seems to react slowly with platinum oxide films on anodically prepolarized electrodes to restore a clean platinum surface. 

Niobium is used as a substrate for platinum in impressed-current cathodic protection anodes because of its high anodic breakdown potential (100 V in seawater), good mechanical properties, good electrical conductivity, and the formation of an adherent passive oxide film when it is anodized. Other uses for niobium metal are in vacuum tubes, high pressure sodium vapor lamps, and in the manufacture of catalysts. 

Pulsed current experiments of aqueous acetate solutions indicate that at least in aqueous solution a platinum oxide layer seems to be prerequisite for the da arboxy-lation to occur. Only at longer pulse durations (> 10 s) is ethane produced [73,74]. These are times known to be necessary for the formation of an oxide film. At a shorter pulse length (<10"" s) acetate is completely oxidized to carbon dioxide and water possibly at a bare platinum surface [75]. The potent dynamic response in the electrolysis of potassium acetate in aqueous solution also points to an oxide layer, whose... 

Another type of supercapacitor has been developed in whieh instead of ideally polarizable electrodes, electrodes consisting of disperse platinum metals are used at which thin oxide films are formed by anodic polarization. Film formation is a faradaic process which in certain cases, such as the further partial oxidation and reduction of these layers, occurs under conditions close to reversibility. 

Anodic passivation can be observed easily and clearly with iron group metals and alloys as shown in Fig. 11-10. In principal, anodic passivation occurs with most metals. For instance, even with noble metals such as platinum, which is resistant to anodic dissolution in sulfuric acid solutions, a bare metal surface is realized in the active state and a superficial thin oxide film is formed in the passive state. For less noble metals of which the affinity for the oxide formation is high, the active state is not observed because the metal surface is alwa covered with an oxide film. 

---