Preparation, Characterization and Proton Conductivity of Layered Cerium Sulfophenylphosphonate

Abstract

Sulfonated cerium phenylphosphonate, Ce (O₃PC₆H₄SO₃H)₂·3.86H₂O, was synthesized to prepare thin film membrane having increased thermal stability, hydrophilicity, and improved methanol crossover resistance. The compound was characterized by X-ray diffraction, FTIR, and TG- DTA analysis. The initial weight of TGA curve extends to 180°C and results from loss of interlayer water in the amount of 10.2% or 3.86 moles. AC conductivity measurements were in-vestigated in the range of 25-200°C as a function of relative humidity. With increasing relative humidity in the range 40-100% at 175°C, the conductivity rises by 1 order of magnitude up to about 0.026 Scm⁻¹. The activation energy of conductivity yields 0.21 eV for the 100-175°C region under P_H2O/P_S= 1.