Fabrication of ceria particles using glycine nitrate spray pyrolysis

• Cerium oxide particles with different morphologies were prepared.
• Porosity and wall thickness of hollow particles have been controlled
• Formation mechanisms of hollow particles have been proposed.

Ceria-based materials are widely used in many industrial applications such as solid-oxide-fuel-cell electrolytes, catalyst supports and carbon monoxide reduction catalysts because of their superior properties. Morphologies of ceria particles have been well-correlated with their properties. Here we show that various morphologies of ceria particles can be achieved by using the mixed precursor solutions of cerium ammonium nitrate and glycine nitrate (GN) for the new method of glycine nitrate spray pyrolysis. Five precursor solutions with the GN concentrations of 0, 50, 60, 67 and 75 mol% have been investigated. The resultant particles show four distinct morphologies of sphere, hollow, flake and porous flake using scanning electron microscopy, transmission electron microscopy and nitrogen adsorption and desorption isotherms. Our results suggest that the morphological formation mechanisms are highly influenced by the factors of precursor solubilities, solvent evaporation rates and precursor thermal properties. In addition, we have demonstrated that the wall thickness of hollow particles can be achieved by selecting the suitable GN concentration range (50–67 mol%).