Comparison of microstructure and hydrogen permeability of perovskite type ACe0.9Y0.1O3-δ (A is Sr, Ba, La, and BaSr) membranes

Abstract

Hydrogen permeation through ACe0.9Y0.1O3-δ (A = Sr, Ba, La, and BaSr) perovskite-type membranes was studied at high temperatures. X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were used to characterize phase structure and phase stability of the membrane. The XRD results showed the formation of a single phase of perovskite structure with configuration orthorhombic for BCY and BSCY membranes. Based on the TGA results, it was found that the phase stability increases in the order of LCY < SCY < BCY < BSCY. The microstructure examinations of the synthesized membranes studied by scanning electron microscopy (SEM) showed the formation of a dense-like grained microstructure membrane, which is applicable for permeation tests. The partial substitution of Sr by Ba in SCY membrane led to an increase of more than 90% in the hydrogen permeation flux; a high permeation flux of about 1.6 ml min−1 cm−2 was achieved at 900 °C with a partial pressure of 0.6 atm. The activation energies for hydrogen permeation increased in the order of BaSr < Ba < Sr < La.