Dispersant- and solvent-free pastes for UV-assisted micro-extrusion of porous proton conductive membrane supports

Proton-conducting ceramic membranes designed with an asymmetric configuration have received increasing attention for their 100% H2 selectivity, high thermo-chemical stability, and intrinsic lower cost respect the Pd–based counterparts. The design of the substrate is of paramount importance to increase the gas diffusivity through the porous support. In this work, porous BaCe0.65Zr0.20Y0.15O3-δ (BCZY) supports were fabricated for the first time via UV-assisted micro-extrusion. Different BCZY-based inks preparation methods were evaluated to obtain high solid loading (> 40 vol%), solvent and dispersant-free eco-friendly formulations. Printable inks with optimal shear thinning behaviour were successfully extruded, depositing up to three stacked layers without defects. Drying and thermal post printing treatments were carefully optimized to obtain defect-free and easy to handle green bodies. The optimization of the whole process leaded to planar BCZY-based supports with a high degree of engineered porosity and suitable mechanical properties to be potentially applied in asymmetric membrane structures.