Evaluation of the Pyrochlore(H3O) SbTeO6 as a Candidate for Electolytic Membranes in PEM Fuel Cells

摘要

((HO)-O-3)SbTeO6 pyrochlore is an excellent fast proton conductor, due to its open crystalline structure and suitable porosity. According to literature it presents a conductivity of 1 x 10(-2) S/cm a 30 degrees C in a saturated water vapor atmosphere. Recently we have described the crystal structure of this pyrochlore, where we have been able to locate the H3O+ species from neutron powder diffraction data. In this work we present the results of conductivity as a function of temperature and relative humidity, as well as a NMR characterization of this appealing compound. At low temperatures the conductivity of the pyrochlore does not vary much, but above 100 degrees C this magnitude increases exponentially. At 160 degrees C sigma= 1.8 x 10(-1) S/cm. At 30 degrees C, the conductivity is 5.0 x 10(-3) S/cm, in contrast with the value reported literature.