Synthesis of monophasic Ce0.5Zr0.5O2 solid solution by microwave-induced combustion method

Abstract

Nanocrystalline monophasic Ce0.5Zr0.5O2 solid solution (1:1 molar ratio) has been synthesized by microwave-induced combustion method in a modified domestic microwave oven (2.45 GHz, 700 W) in approximately 40 min from cerium nitrate and zirconium nitrate precursors using urea as ignition fuel. For the purpose of better comparison, a CexZr1 − xO2 solid solution (1:1 molar ratio) was also synthesized by a conventional co-precipitation method from nitrate precursors and subjected to different calcination temperatures. The synthesized powders of both methods were characterized by means of X-ray powder diffraction, thermogravimetry/differential thermal analysis, scanning electron microscopy, and BET surface area techniques. Oxygen storage capacity (OSC) measurements were performed to understand the usefulness of these materials for various applications. The characterization results reveal that the sample obtained by microwave-induced combustion-synthesis route exhibits homogeneous monophasic Ce0.5Zr0.5O2 solid solution whereas the co-precipitated sample displays compositional heterogeneity. The OSC measurements reveal that the materials synthesized by both methods exhibit comparable oxygen vacancy content (δ).