Preparation, sintering, and water incorporation of proton conducting Ba0.99Zr0.8Y0.2O3−δ: comparison between three different synthesis techniques

Three wet chemistry routes were used to synthesize Ba0.99Zr0.8Y0.2O3−δ (BZY20) and to avoid the drawbacks of the conventional mixed oxide route used for its preparation. Pure samples were prepared using the Matrix Trapping and Decomposition (MTD) and Polyacrylamide Gel (PG) processes. The compound as a powder is thermodynamically stable up to 1250 °C while the purity of the bulk of a pellet can be maintained up to 1500 °C. An expected increase of the lattice parameter (from 0.4193 (BaZrO3) to 0.4228 (1) nm (BZY20)) was observed confirming the dissolution of yttrium in the barium zirconate structure. BZY20 absorbs large amounts of water vapor (H/Ba≈0.19) and pellets can be sintered up to 95% at 1500 °C for 10 h.