A novel method for preparing highly porous gadolinia-doped-ceria ceramics

Highly porous Ce0.8Gd0.2O1.9 (CGO) was prepared with a novel method by acid leaching MgO from MgO–CGO ceramics (CGM) with acetic acid solution. Effects of leaching conditions and MgO content in CGM were studied. Under proper conditions (60 vol% acetic acid solution, 358 K, 8.5 h), MgO in CGM ceramics can be effectively leached out, but no CGO can be dissolved. The porosity of the sufficiently leached pellet increases with the increasing MgO content, but too much MgO can result in the collapse of the leached pellet. The suitable value of MgO/CGO is about 3.3. With the novel method, a highly porous CGO pellet was prepared with a porosity of 68% which is much higher than that (∼50%) with graphite as pore former.