Porous Y2O3-stabilized ZrO2 (YSZ) samples were synthesized
by preparing NiO/YSZ composites by tape casting and calcining
at 1800 K, reducing the NiO to nickel in H2 at 973 K, and
finally leaching the nickel out of the structure with 2.2M HNO3
at 353 K. Porous YSZ was prepared from NiO/YSZ composites
containing 0, 20, 40, and 50 wt% NiO. Complete removal of the
nickel was demonstrated by XRD, weight changes, and porosity
increases. Porosities >75% could be achieved without
structural collapse of the YSZ phase. Finally, the method was
applied to the fabrication of a solid oxide fuel cell with a
copper-based anode operating on H2 and n-butane.
