Composite proton-conducting materials containing mordenite and micro-particulate hydrous Sb2O3 were prepared. The materials were characterized by means of X-ray powder diffractometry, 29Si and 27Al MAS-NMR, 121Sb Mössbauer spectroscopy and ac conductivity studies. Sb2O3-mordenite composites exhibited (figure 12) conductivity enhancements (relative to parent Na mordenite) which were similar to those reported for so-called tin mordenite; the components of both systems comprised a hydrous oxide and de-aluminated zeolite. Both XRD and MAS-NMR exhibited de-alumination/disruption of the framework of the zeolite to be less extensive than in previously investigated composites of antimonic acid and mordenite, which did not exhibit conductivity enhancement.

Structure and Enhanced Proton Conductivity in Composites of Antimony(III) Oxide and Mordenite. R.C.T.Slade, G.B.Hix, B.Ducourant: Solid State Ionics, 1997, 99[3–4], 233–9