Characterization of potassium salts of 12-tungstophosphoric acid

• Published in: Materials research bulletin Vol. 45; no. 11; pp. 1679 - 1684
• Main Authors: Holclajtner-Antunovic, I., Mioc, U.B., Todorovic, M., Jovanovic, Z., Davidovic, M., Bajuk-Bogdanovic, D., Lausevic, Z.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01-11-2010
• Subjects: A. Superconductors; ABSORPTION SPECTROSCOPY; B. Proton conductivity; C. Electron microscopy; C. Infrared spectroscopy; C. Raman spectroscopy; C. Thermogravimetric analysis; FOURIER TRANSFORMATION; FUEL CELLS; INFRARED SPECTRA; MATERIALS SCIENCE; POTASSIUM; POTASSIUM IONS; PROTON CONDUCTIVITY; PROTONS; RAMAN SPECTROSCOPY; SALTS; SCANNING ELECTRON MICROSCOPY; STRUCTURAL MODELS; SUPERCONDUCTORS; THERMAL GRAVIMETRIC ANALYSIS; TUNGSTOPHOSPHORIC ACID; C. Electron microscopy; C. Raman spectroscopy; B. Proton conductivity; A. Superconductors; C. Infrared spectroscopy; C. Thermogravimetric analysis
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2010.06.064

Potassium salts of 12-tungstophosphoric acid with varying amounts of cation, K
x
H
3
−
x
PW
12O
40 (
x
=
1, 2, 3) have been prepared and their characteristics investigated by thermal analyses, FT-IR and micro-Raman spectroscopy and SEM-EDS analysis. It was found that the number of replaced protons by potassium ions in the 12-tungstophosphoric acid structure has influence on the presence of different protonic species, their dynamic equilibrium and on the conductivity of salts. The results reported in this study have been applied to improve the structural model of insoluble acidic salts. It is shown that an acidic potassium salt presents a mixture of neutral salt and unreacted acid. The nature of this mixture depends on the number of replaced protons-oxonium ions by cations. Preliminary measurements with synthesized compounds as solid electrolytes in fuel cells have been done, too.