Ultrafine ceria powders via glycine-nitrate combustion

Abstract

The ultrafine ceria powders have been synthesized by the combustion technique using glycine as a fuel and nitrate as an oxidizer. The auto-ignition (at ≈200°C) of the viscous liquids containing cerium nitrate and glycine resulted in voluminous ceria powders. An interpretation based on an adiabatic flame temperature, for different fuel-to-oxidant ratios, has been proposed for the nature of combustion and its correlation with the powder characteristics. The combustion synthesized ceria powders have been characterized by XRD, HRTEM, surface area analysis, and sinterability. Specific surface area and primary crystallite size of the ceria powder obtained through fuel-deficient precursor was found to be ≈75 m 2/g and 2.5–12 nm, respectively. The powder, when cold pressed and sintered in air at 1250°C for 1 h, attained the sintered density ≈94% of its theoretical density, with submicron grain size.