Hydration and Proton Transport in Solid Solutions Based

Hydrated alkaline-earth metal tungstates Ba 4 Ca 2 + x W 2 - x O 12 - 2 x with perovskite structure were studied by the thermogravimetry, 1 H NMR, IR, and Raman spectroscopy methods. Electrical conductivity and transfer numbers were measured with varying T , , and . The solid solutions are capable of reversibly intercalating water and can exhibit high-temperature proton transport. The localization of protons on oxygen results in the appearance of energetically nonequivalent OH groups; a small fraction of protons are present in the form of H 2 O and H 3 O + .