Cationic and anionic frameworks of La5.4MoO11.1 proton
conductors have been modified by means of metal (Ti4+, Zr4+, and Nb5+) and
fluorine (F−) doping. This synergic effect leads to the stabilization of highsymmetry
and single-phase polymorphs. The materials have been fully
characterized by structural techniques, such as X-ray and neutron powder
diffraction and transmission electron microscopy. The fluorine content was
determined by ion chromatography. Impedance spectroscopy analysis under
different atmospheres (dry and wet N2 and O2 and wet 5% H2−Ar) showed
an improvement in the electronic conductivity under reducing conditions,
making these materials potential candidates for hydrogen separation
membranes.
