Organic additives, underpotential deposition

Finally, it should be mentioned that by the presence of certain additives the underpotential deposition process can be inhibited. Upd of copper on Pt(lll), Pt(lOO), and Pt(llO) can be inhibited by thiourea and dithiadecyldisodium sulfonate. The results of a study on the effects of organic adsorbates on the underpotential deposition of silver on Pt(lll) electrode show that the presence of coadsorbates (2,2-bipiridyl, 4-mercapto-pyridine, etc.) can have a pronounced effect on the underpotential deposition. It has been found that adsorbates that bind primarily through a ring nitrogen atom inhibit the second, but not the first, silver monolayer. In contrast, the sulfur-containing adsorbates inhibit the formation of the first monolayer owing to the formation of the Pt-S bond. 

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