SrZr0.9Y0.1O3−δ thin films by in-situ synthesis of triple alkoxide for protonic ceramic electrolyser membranes

Abstract

[EN] Synthesis of the proton-conducting electrolyte SrZrYO(SZY) was undertaken by the sol–gel method employing an all-alkoxide route from reaction of strontium alkoxide produced in-situ and commercial zirconium and yttrium alkoxides. The solution was homogenized by a previous ligand exchange in 2-methoxyethanol to control the polycondensation rate and achieve SZY at the low final firing temperature of 700–800 °C. SZY thin films (~270 nm) were assisted by dip-coating on different substrates and characterized by scanning and transmission electron microscopy, grazing X-ray diffraction and confocal micro-Raman spectroscopy, revealing well-crystallized SZY phase with orthorhombic symmetry (space group, Pnma). Impedance spectroscopy of a thin film deposited on a quartz substrate revealed that protons contribute to transport in wet conditions as confirmed by a lower conductivity in DO-humidified air (1.02 eV) compared to HO-wetted air (0.99 eV), with the difference in activation energy consistent with a conductive isotope effect. [Figure not available: see fulltext.].