Interconversion of a bisulfate anion into a sulfuric acid molecule on a Pt(111) electrode in a 0.5 M H2SO4 solution

✍ Scribed by Y. Shingaya; M. Ito

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 454 KB
• Volume: 256
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(96)00465-4

✦ Synopsis

The coadsorption of water and sulfur trioxide (503) molecules on Pt(lll) was studied by thermal desorption spectroscopy, in-situ and non-situ infrared reflection absorption spectroscopy in order to reveal a double layer structure on a Pt(111) electrode surface in a 0.5 M H2SO 4 acid solution. The vibrational frequencies of water, bisulfate and sulfuric acid molecules adsorbed on ultra-high vacuum (UHV) model surfaces at temperatures of 110-300 K were compared with those from a real double layer in a 0.5 M H2SO 4 acid solution under active potentials. Model structures on Pt(l 11) under UHV obtained from surfaces after a lower-and a higher-temperature annealing agreed well with those from surfaces at a negative and a positive electrode potential, respectively. A sulfuric acid molecule on a Pt(111) electrode observed at 750-1100 mV was reproduced by dehydration from the coadsorbates of H3 O+ and HSO4-at 200-300 K.