Underpotential deposition of zinc ions on polycrystalline platinum: FTIR and EQCM study

✍ Scribed by Akiko Aramata; Satoru Terui; Satoshi Taguchi; Toshikazu Kawaguchi; Katsuaki Shimazu

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 608 KB
• Volume: 41
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(95)00364-9

✦ Synopsis

Underpotential deposition(UPD) of ZnZ+ Ions on polycrystalline platinum in KH,PO, solution (pH 4.6) was studied by Fourier transform infrared reflection spectroscopy (FTIR) and electrochemical quartz crystal microbalance (EQCM). By the addition of Zn2+ ions in KH,PO, solution, the intensities of ir bands of around 990, 1044 and 1090cm-' are increased with a negative increase of potentials at E I 0.7V (rhe) where Zn UPD takes place, while by EQCM the weight increase of Pt mounted quartz was observed in the same potential region. Coverage of UPD Zn was 0.75 at 0.05 V as two-electron transfer UPD process, being estimated from cyclic voltammogram, and mps (mass number per platinum sites) was 78 by EQCM; from both values the coverage of phosphate was evaluated as 0.27.

These results are discussed that the phosphate species adsorbs over UPD Zn on Pt as a form of HPO, , where one of three P-O's seems to be bound to UPD Zn on Pt.