Development and hydrogen permeation of freeze-cast ceramic membrane

BaCe0.65Zr0.20Y0.15O3-δ - Gd0.2Ce0.8O2-δ (BCZY-GDC) is currently one of the most investigated composites as ceramic membranes for H2 separation and membrane reactors. In this context, we will present for the first time the possibility to exploit the ice-templating method coupled with screen printing to obtain hierarchically-structured proton-conducting ceramic membranes. All the processing steps to obtain a defect free dense/porous structure were considered and analysed. In particular, the formulation of screen printing ink was optimized in terms of nature/amount of deflocculant and type of starting BCZY powder. An innovative membrane constituted by a 50 %-porous support with well-organized and aligned porosity and a 13 ± 3 μm thick dense layer on the top, was produced. The compressive strength (20.6 ± 5.6 MPa), were considered acceptable for practical applications. Promising H2 fluxes of 0.36 and 0.42 mL min-1 cm−2 at 750 °C, using a feed stream with 50 and 80% H2 in He (H2 %vol.) respectively, were obtained.