Oxide formation platinum

Anderson also accepted the model of etching by platinum oxide formation and volatilization, yet the results clearly demonstrate that the surface area increase and etching rate correlate with local reaction rate and not oxygen concentration. No control experiments (e.g., with the sample in pure oxygen) were conducted to test the model. 

FIGURE 3.18 A comparison of the proposed model of surface oxide formation and reduction at Pt(lll) in nonadsorbing acidic electrolyte with CV data of Gomez-Marin et al. (2013). The scan rate varies by four orders of magnitude from (a) to (f), as indicated in the plots. (Reprinted from Electrocatalysis, Mechanistic principles of platinum oxide formation and reduction, 2014, 1-11, Rinaldo et al. Copyright (2014) Springer. With permission.)... 

Rinaldo, S. G., Lee, W., Stumper, J., and Eikerling, M. 2014. Mechanistic principles of platinum oxide formation and reduction. HcctTwcala/ysis, 1—11, EXDI10.1007/Sl 2678-014-0189-y. 

Conway et al. (Angerstein-Kozlowska et al. 1973 Conway 1995) summarized earlier work on platinum oxide formation in the potential region of 0.85-1.lOV in an HjSO solution, adsorbed species (OH ) are formed by the oxidation of H O molecules (4). The OH and platinum surface atoms then undergo place-exchange, forming a quasi-3D lattice (5). At higher potentials (1.10-1.40 V), the OH species in this lattice are oxidized, generating a Pt-O quasi-3D lattice (6). 

CVs in Oj-saturated H SO solution containing MeN ", and EtN ions did not show significant changes from those in pure H SO, as long as the amount of impurity was not large (1% of H+). In the case of PrN" or BuN ", hydrogen adsorp-tion/desorption peaks as well as platinum oxide formation/reduction peaks were distorted even for the lower amount of 0.1%. 

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