2007/03/28 by Jalal Ghilane, Corinne Lagrost, Maryline Guilloux‐Viry +4 · 1 citation
Energy · Engineering · Materials Science · #Electrocatalysts for Energy Conversion #Semiconductor materials and devices #Catalytic Processes in Materials Science
paper · doi:10.1021/jp068879d
openalex publication_date 2007/03/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22
Electrochemical “reduction” of Pt was investigated using electrochemical and X-ray photoelectron spectroscopy (XPS) techniques. This transformation of a platinum metal, which is possible with a large variety of organic and inorganic cations, was investigated in DMF containing CsI salts chosen as a test system. Experiments show that considerable modifications of the chemical nature of the starting material accompany the morphological changes that were previously reported. With rather mild reduction conditions, cesium-platinides-like structures were detected. XPS investigations bring a direct spectroscopic evidence for the formation of a reduced platinum state from a metallic electrode held at a negative potential. XPS spectra clearly showed a significant and continuous shift of the Pt formal oxidation degree with the injected charge of −1.6. This behavior is analogous to a charging process. Additionally, proofs of the full reversibility of the phenomenon was provided by the XPS analyses showing that the “reduced Pt” returns to its metallic state after reaction with a diazonium salt. It is noticeable that the formation of negative oxidation state of Pt exists even when a large competitive electrochemical process occurs, as in our case with the reduction of protons from residual water.