Iron alloys, surface preparation

Frankenthal, R. P., The Effect of Surface Preparation on Pitting and Anodic Dissolution of Iron-Chromium Alloys , J. Electrochem. Soc., 114, 201c (1967)... 

A point often neglected is the handling procedure between preparation of the surface and immersing the specimen in the test medium. For instance, oxide film formation on oxide-passive materials and or tarnishing layers on copper or iron alloys formed at this stage can influence the electrochenucal behaviour considerably these chemical changes on the surface depend on such factors as temperature, humidity and time [5]. 

A third way to increase both the active surface area and the number of oxygenated species at the electrode surface is to prepare alloy particles or deposits and then to dissolve the non-noble metal component. This technique, which is similar to that used to prepare Raney-type catalysts, yields very high surface area electrodes and hence some improvements in the electrocatalytic activities compared with those of pure platinum. However, it is always difficult to be sure whether the mechanism of enhancment of the activities is due to this effect or the possible presence of remaining traces of the dissolved metal. Results with PtyCr and PtSFe were encouraging, although the effect of iron is still under discussion. From studies in a recent work on the behavior of R-Fe particles for methanol electrooxidation, it was concluded that the electrocatalytic effect is due to the Fe alloyed to platinum. ... 

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