Electrofluorination of hexafluorobutanol in anhydrous hydrofluoric acid - Quasi on line mass spectrometry and X-ray photoelectron spectroscopy studies

Certain aspects of the electrochemical fluorination (ECF) of hexafluorobuta nol (HFB) in anhydrous HF (AHF) on Ni electrodes have been examined by mass spectrometry (MS) and X-ray photoelectron spectroscopy (XPS). Measurements were performed using a portable ultrahigh vacuum compatible chamber that a llows for the transfer and characterization of specimens without exposure t o the ambient atmosphere. Quasi on line MS analysis of the gases released d uring ECF of HFB/AHF solutions revealed features attributable to perfluorob utyryl fluoride [PBF = CF3CF2CF2C(O)F] with no evidence of the presence of other reaction products. Ex situ XPS analysis of Ni electrodes following EC F yielded spectra consistent with the formation of a rather thick, irregula r layer of NiF2 of average thickness of about 150-200 monolayers, with smal l contributions due to O (6% ) and C (7%) localized primarily in the surfac e region. (C) 2001 The Electrochemical Society.