Changes in real surface area, crystallographic orientation and morphology of platinum electrodes caused by periodic potential treatments: phenomenological approach

Abstract

The changes in surface structure of polyfaceted single crystal platinum spheres subjected to repetitive square-wave potential treatments in acid solution have been studied. The dependence of the prevailing type of change on symmetry, potential limits and frequency of the periodic potential has been determined. Results are discussed on the basis of different reactions occurring within definite potential windows and distinct rate controlling processes depending on the operating conditions. Accordingly, the surface restructuring involves a predominant change in either the real surface area, the cr :stallographic orientation or the entire surface morphology .

Sequential and simultaneous electrodeposition of Pt–Ru electrocatalysts on a HOPG substrate and the electro-oxidation of methanol in aqueous sulfuric acid

“…In addition, one should consider that, from procedures I and II, some electrochemical faceting of noble metals (platinum, palladium, ruthenium) by applying triangular periodic potential routines in aqueous acids also occurs [55][56][57][58][59][60].…”

Electrochemical Behavior and Semiempirical Approach to the Electroadsorption of 3-Buten-2-one and 2-Butanone on Platinum

“…1). This surface exhibits a high proportion of reaction sites equivalent to stepped planes of narrow (111) terraces (13,27). On the other hand, when a pc Pt electrode was subjected to a SSWPR between 0.05 and 1.50 V at 5.5 kHz for 5 min in the background solution, a new surface resulted in a high proportion of sites with narrow terraces of (100) planes (16,28) (Fig.…”

“…The application of potential periodic routines on noble metal electrodes produces either instantaneous or permanent morphological changes, depending on the characteristics of those routines. Fast symmetric potential perturbations applied to Pt electrodes in acidic media produce permanent changes in the morphology of the surface, that is, a new defined crystallographic orientation and/or a certain surface roughness (13,18). The electrochemical responses of the resulting interfaces are generally different from those of the initial ones and the electrocatalytic activities of the studied processes exhibit new interesting features (14 -18).…”

The Influence of electrochemical surface modifications on naval steel corrosion

“…It has been found that the application of a PPP can produce dramatic changes on the morphology and crystallography of metal electrodes [8,10,11]. In the case of ferrous metals, there are some papers dealing with the effects of periodic potential programs [15,18].…”

“…Previous studies on noble electrodes in acid media have demonstrated the possibility of changing the distribution of the surface crystallography and surface roughness using these methodologies [8]. The application of these PPP on metal electrodes produces either temporary or permanent morphological changes, depending on the applied frequency and potential limits [9][10][11]. Thus, the application of a fast (larger than 2 kHz) symmetric PPP on noble metal electrodes in acid media develops new crystallographic planes without changes in the surface roughness [11,12].…”