Low-temperature preparation of BaCeO3 through ultrasonic-assisted precipitation for application in solid oxide electrolysis cell

Abstract

Barium cerate (BaCeO3) was synthesized using conventional precipitation and ultrasonic-assisted precipitation. The effect of precipitation parameters (precipitation precursor, precipitation agent, agent concentration and temperature) significantly affected %perovskite formation and crystallite size of the product. Precipitation with 1 M (NH4)2C2O4 induced the formation of a single-phase BaCeO3 while precipitation with 5-20 M NaOH provided a mixed phase of BaCeO3 and CeO2. The %perovskite increased as increasing precipitation temperature; however, the crystallite size of the product also increased. Increasing ultrasonic intensity (30 and 150 W cm-2) during precipitation was found to increase the %perovskite and to reduce crystallite size. The precipitation with 1 M (NH4)2C2O4 agent, using ultrasonic intensity at 150 W cm-2, provided single phase BaCeO3 with crystallite size of 18.4 nm after calcination at 900 °C for 4 h. The electrochemical performance of the BaCeO3 cell under steam electrolysis condition (controlled voltage from OCV to 1.5 V; 20% H2O, 40% H2, and 40% N2) was measured (600-800 °C) and the activation energy of conduction was calculated to be 0.78 eV.