XPS study of titanium species exposed to molten Li2CO3-Na2CO3 in the anodic conditions used in molten carbonate fuel cells

The surface characterization of titanium, titanium oxide and lithium titana te samples exposed to molten Li2CO3-Na2CO3, in the anodic conditions used i n molten carbonate fuel cells, was carried out by X-ray Photoelectron Spect roscopy (XPS). Different elements were identified: Ti(IV), O(-II), Li(I) an d Na(I). The amounts of adsorbed sodium and lithium carbonates, as well as inserted lithium were estimated by a semi-quantitative XPS analysis in laye rs of about 50 Angstrom. A broadening of the Ti 2P(3/2) peak was observed. This effect is probably caused by a distorsion of the Li2TiO3 lattice due t o the incorporation of lithium within this structure. Li2TiO3 compound was detected by X-ray diffraction (XRD) on Ti, TiO2 as well as Li2TiO3 after tr eatment in the molten carbonate eutectic. (C) 1999 Kluwer Academic Publishe rs.